The industrialist Sir Derek Hornby once related the following exchange: he was having a drink with Lord Lawson when his friend asked: 'Derek, you've got famous children, haven't you?' Hornby replied: 'Yes, I suppose I have - and a famous son-in-law.' (Sir Derek is the father of novelist Nick Hornby and father-in-law to novelist Robert Harris.)

Lawson pondered this, then asked: 'Do you find that people are more interested in your children than you?' (Lawson is the father of celebrity cook Nigella and journalist Dominic.)

Hornby considered. 'Yes, I suppose I do. It's rather nice, really.'

'So do I - and I was Chancellor of the Exchequer,' replied Lawson senior, with a twinkle in his eye.

Time moves on. Lord Lawson of Blaby, Chancellor of the Exchequer from 1983 to 1989, and before that a distinguished journalist on the Financial Times, the Sunday Telegraph and the Spectator (which he edited), is back in the news.

Lawson's contrarian stand on global warming has attracted much attention. His position is also more subtle than sometimes made out: he is quite happy to have fun by pointing out how often the scientific consensus of previous centuries was overturned by subsequent events and discoveries. But the gravamen of his attack is not so much his questioning of the science - Lawson is not in the George W Bush denial camp - as his scepticism about the conventional view as to what the response should be.

When I told my old friend Nigel Lawson about this occasional series of interviews with former Chancellors, he quipped: 'You'll be on to Gordon Brown before long.' Having agreed to meet, he suggested that we do the interview in France, where he spends part of the year in what is, given his latest campaign, semi-retirement at most. The attractions of a trip to deepest Gascony spoke for themselves. And when I consulted about hotels, he and his wife Therese generously recommended Chateau Lawson.

No, it is not called that, but their converted 18th-century house - remote and peaceful at the end of an avenue of cedars near a deserted mill - used to be an Armagnac domaine. When he is out there, the former Tory statesman relishes the old-fashioned, courteous way of life in the local towns and villages - a refreshing contrast to a Britain whose loss of much of that sense of repose may not be unconnected with certain aspects of the Thatcherite reforms behind which Lawson was such a driving force. If Nicolas Sarkozy has his way, that way of life could come under threat in France as well.

As it happened, the French were voting for a new president on the weekend when our rendezvous took place. Lawson was supporting Sarkozy, while his wife and I were on the losing side - not for the first time in political battles with Chancellor Lawson. He was a strong Chancellor with a first-class intellect, the sort of boss the Treasury admires.

One of the purposes of this series is to allow for reflection after contemporary controversies have died down. And there were plenty of those during Lawson's tenure - well and honestly documented in his brilliant memoir, The View From No 11.

One of the many attractive things about Lawson - and I write as a commentator who was continually critical of his policies, while getting on well with him personally - is his directness. He did not wish to talk about his difficult relationship with Margaret Thatcher - 'I have said enough about that in my memoirs' - but he was at pains to set the record straight about the issue that eventually led to his resignation: the 'shadowing' of the deutschmark, his advocacy of membership of the exchange rate mechanism and the associated difficult relationship with Thatcher's economic adviser, Sir Alan Walters.

'People are puzzled that I proposed ERM membership and opposed European economic and monetary union. But EMU is not in Europe's interest and certainly not in Britain's interest. EMU is essentially a political step - a means of intensifying European political integration. In my view, there are some advantages, but there is no net economic advantage - indeed, there is a net disadvantage. But joining ERM was something I saw as a purely economic step.'

When the pound eventually entered the ERM, a year after Lawson's resignation, the adventure lasted only two years and ended in political disaster. But Lawson now reveals that he intended it as a temporary measure - 'membership only needed to last until we'd achieved a sufficient record in lowering inflationary expectations and overcoming our inflationary psychology'.

In which context he praised Mervyn King, the current governor of the Bank of England, for attaching great weight to inflation expectations, and was especially interesting in commenting on the criticism he had received in the Eighties for describing inflation as 'a blip' (when it turned out not to be) and as the 'judge and jury' (of monetary policy).

The Chancellor who did so much to promote monetarism in the early days reflected: 'Counter to the extreme monetarist view that you just control the money supply and that's what it's all about - even if you know what the money supply is - a lot of the remarks one makes as Chancellor are attempts to generate expectations in a favourable way. They are operational, not prediction.'

This struck me as a fair point, and of some interest to those who criticised him at the time. But the fact of the matter was that, on the inflation front, Chancellor Lawson ran into trouble. His failure to control inflation expectations, along with the 'Lawson boom' and the troubles with Thatcher and Walters, became the first draft of the history of his Chancellorship.

When I had first asked him about 'regrets', he had insisted that he did not like to dwell on the past. He naturally regrets the events that led to his resignation, 'but I really don't believe in brooding, because you can't do anything about it. Indeed, for the same reason I don't even spend time thinking about things that went right. I believe in moving on - which is one reason why I am so involved in the climate change issue.'

Nevertheless, he courteously allowed me to return to the Walters issue and summed it up thus: 'Walters was extremely useful when he was at the Treasury full time in the early Eighties. He was outspoken as an adviser and rightly so [the Treasury had made sure that, although at Number 10, Walters was given all the relevant papers]. But when he returned as a part-time adviser he had become a minor public figure, making public statements that were incompatible with the status of an adviser.'

The focus of Walters's criticisms was the former Chancellor's obsession with the ERM, but it sounds as though, if Walters had been more aware of Lawson's real strategy - temporary ERM membership to cure inflation - things might have turned out differently. But, as Lawson says, no point in brooding.

Nevertheless, he believes that too little attention is paid in this country to economic history. 'If you look at past cycles, you understand a great deal more, not least about inflation.'

This brought him to think aloud. 'Curiously enough, I missed out on the fact that we were embarking on globalisation. I was not aware how far it was going to develop. It's been extremely beneficial, and the emergence of China means that global inflationary pressures have abated to an immense extent.

'Of course, Gordon Brown claims the credit. I didn't see globalisation coming, but am glad it has. Perhaps I was excessively concerned with the problems of inflation at the expense of doing more on the supply side.'

But, let's face it, he did quite a lot on that front. Asked what he was most proud of in his Chancellorship, he had no reservations: 'Playing a significant part in what I thought was the transformation of the British economy in a way that to a considerable extent has endured.

'What motivated me was that it seemed to me things needed to change. It was a lot of hard work, but unrewarding work if things were to be undone by the next government. Therefore it was important to remain in office long enough so that what we did was not overturned. Broadly and to a considerable extent - not totally - that happened.'

In other words New Labour, after all those years of opposition, broadly accepted the Thatcher/Howe/Lawson settlement.

This gave me the opportunity to make the point that all the familiar tales about Walters, the ERM and the problems with the Lawson boom have diverted attention from the fact that like it or not - and some of us don't - Labour has not dared to reverse Lawson's amazing 1988 Budget strategy, when he brought the top rate of income tax down to 40 per cent and the basic rate to 25 per cent. Quick as a flash, he replied: 'Not yet they haven't.'

We were conversing on the terrace, with an idyllic view of the Gascon countryside. Things became even more idyllic when my host - it was now midday - gently suggested: 'Do you think we have done enough of this interview to treat ourselves to a drink before we go on?'

Your correspondent batted for England and gamely concurred. We had a glass of floc, a Gascon aperitif of white wine laced with Armagnac - apparently invented when overproduction of the local spirit threatened to drive the price down and new uses were required. But before the first sip, Lawson excitedly said: 'I've just remembered a Big Regret'. He repeated: 'A Big, Big Regret.'

I put down my undrunk glass and took up my pen. 'I very much regret that Margaret prevented me from giving the Bank of England independence. I'd proposed it in 1988. It was fully worked out. It would have been much better for the Conservative Party if it had been implemented.'

As we sipped our floc, I reminded Lord Lawson - still not yet fully retired - that he had once expressed a desire to retire to Greece. 'It was Mycenae,' he recalled. 'This is a compromise - halfway to Greece. I can speak the language - I can't speak Greek; and when we are here I can leave in the morning with the benefit of the hour's difference, fly from Toulouse and be in the House of Lords by lunchtime.'

Which brings us back to current preoccupations: Lawson's active membership of the high-powered House of Lords economics committee, which has already reflected his sceptical view on global warming. I got the impression that he would have liked at least half of our interview to be about global warming, but trust that he appreciates that there is still a lot of interest in the Chancellorial history of the father of Nigella.

At any rate, he expatiated enthusiastically on the way he was attracted by the 'multi-dimensional' aspects of global warming - the science, the economics and the politics. Whatever the mounting scientific evidence, he believes the economic implications - the choices, the complications, the alternatives - are not fully understood.

'It has always seemed to me that the economic dimension is very important, but also very neglected. People thought that once the science was straightened out - and it is true that there is not a lot of scope for differences in the science - all would follow. But it doesn't. It is not at all clear what makes economic sense - or what is politically feasible.'

Lawson insists that the conventional view - urgent action now to help future generations - is unfair. 'How big a sacrifice is it reasonable to ask people today to bear, in order to benefit generations 100 years hence who'll be substantially better off than we are today?' he asks.

He is fully in sympathy with the Chinese for resisting the Kyoto-type approach. 'I understand their view entirely. I've no time for the Chinese regime, but they have a huge population, most of whom are extremely poor, and the most important thing is to lift them out of poverty because otherwise they'll die in large numbers. They need the fastest possible rate of growth, and that means the cheapest energy. The point is that the Chinese are not prepared to sacrifice the present generation for the generation 100 years hence, and that is absolutely understandable.'

The old Chancellor with a new cause is insistent: 'The idea that the European Union should take the lead [over global warming] and that the UK should lead within the EU only means we suffer, because we lead and others don't follow.'

He is quite determined, and fully aware of the risks to his reputation in the face of what has become a formidable and fashionable consensus. With that familiar twinkle in his eye, he added: 'As a superannuated has-been, I've got involved because political correctness makes it damaging for anyone in politics to speak out. I don't need to worry.'

Indeed, my host went on to say that he has had a big response from the public. 'My postbag, or should I say my email bag, has been overwhelmingly favourable.'

So there you are. Watch out Nigella, dad's back in town, and clearly only semi-retired in Gascony. And by the way, the Chancellor who surprised everybody by slimming drastically and producing a related book on the subject, seems to his weekend guest to be in very good shape. Despite my age advantage on a man who recently celebrated his 75th birthday, I could not beat him at ping-pong.

Life and times: big bang and boom

Nigel Lawson was born on 11 March 1932 and educated at Westminster School and Christchurch College, Oxford (gaining first-class honours in PPE). He did National Service in the Royal Navy, eventually commanding a small torpedo boat. He was married for the first time in 1955 to Vanessa Salmon, heiress to the Lyons Corner House empire. Their four children include Dominic, former editor of the Sunday Telegraph, and TV cook Nigella. He was City editor of the Sunday Telegraph for two years from 1961 and, after a spell as special assistant to PM Sir Alec Douglas-Home, edited the Spectator from 1966 to 1970.

He became MP for Blaby in Leicestershire in 1974. As a backbencher he co-operated with Labour MPs Jeff Rooker and Audrey Wise to secure automatic indexation of tax thresholds. In government from 1979, he was Secretary of State for Energy from 1981 to 1983, preparing for the 'inevitable' miners' strike and paving the way for privatisation of the gas and electricity industries.

In 1983 Margaret Thatcher appointed him Chancellor of the Exchequer, a post he held until 1989. As such he was responsible for reducing income tax (particularly the top rate, which he cut to 40 per cent) and deregulating the City of London for the 'Big Bang'. His policy of shadowing the Deutschmark as a substitute for entry to the European exchange rate mechanism - which he desired and Thatcher opposed - led to increasing tension between them, which came to a head after she reappointed Professor Alan Walters as her economic adviser. Lawson resigned.

He married for a second time in 1980, to Therese Maclear, with whom he had two more children and co-wrote The Nigel Lawson Diet Book. He became Lord Lawson of Blaby in 1992.

· This article was amended on May 29 2007. We placed Nigel Lawson's former constituency, Blaby, in Northamptonshire; it's in Leicestershire and the constituency will be renamed South Leicestershire at the next election. This has been corrected.