Today, in front of the health select committee in the Commons one of the bravest and best elements of the NHS has been giving evidence against Vertex, a pantomime-villain US drug company. Caught in between are unfortunate patients also giving evidence today about their need for Vertex’s cystic fibrosis drug Orkambi, which Nice is so far refusing to approve.

This is an everyday painful dilemma in the life of Nice – the National Institute for Health and Care Excellence – one of the Blair government’s best creations. With transparent criteria, panels of expert and lay assessors examine the evidence to decide which new drugs offer enough new benefit at an acceptable price. The Nice rule of thumb (there are exceptions) is a price of some £30,000 for every good year of life gained by a patient – a QALY – a quality-adjusted life-year.

This is the only logical way to ration the NHS’s resources, trying to treat all patients equally, regardless of their ailment – and it has never been over-ruled by politicians. The media makes most noise about new cancer drugs, but there’s no reason for cancer patients to get more expensive treatments per QALY than those with other conditions. Cystic fibrosis tugs especially hard at the heart strings as in the UK it affects some 10,400 children and young people, who are unlikely to live beyond 31.

Protesters have been campaigning for access to Orkambi with posters reading: ”Don’t put a price on our life.” But what the committee sees today is the brutal fact that every life and every treatment does have a price. The NHS always has and always will ration – it would do so even with a budget twice the size. Nice is 20 years old this year and has succeeded in holding the ring fairly against competing drugs and diseases, despite lobbying drug companies stirring up patient groups to fight for their new products, which often only offer marginal or benefits – or sometimes no new benefits – at high cost.

Vertex is trying to sell Orkambi, the first drug to treat cystic fibrosis’s underlying genetic causes, to the NHS for £105,000 per patient per year. Nice says it’s not a cure, but would like to offer it. But this astronomic price doesn’t compare well with improvements that might be bought for patients with other conditions. Andrew Dillon has been Nice’s chief executive for all of its 20 years, and he says it always reaches a deal with drug companies. He offered Vertex £500m to use its drugs for five years – but it has refused outright to give an inch. “This is the most inflexible company we have come across in 20 years,” he says. “Nothing in [its] evidence suggests anything unique about [its] drug that puts it outside our normal price criteria.” He says Vertex has a better drug in development that might make more impact.

Vertex’s reputation for greed has been enhanced by yesterday’s Guardian revelation that the company has paid almost no UK corporation tax, diverting costs to its Boston-based parent company. This is despite receiving £7m in tax credits from the UK government for investing in research and development. This will further outrage desperate families of cystic fibrosis sufferers, who see Vertex’s soaring profits, up 29% in 2017. Vertex’s CEO, Jeffrey Leiden, earned $78.5m in 2017, and in July he sold shares worth $22.4m. The two British vice-presidents, Simon Lem and Simon Bedson, were paid a total of £1.1m in 2017.

Lem told the trade website Pharmafile in June: “You are humbled every day by the courage of people with CF, their families and carers.” Just not humbled enough, it seems. Did the health committee enjoy Vertex’s hypocrisy?

But is its obduracy pure greed or is there something more sinister behind its exceptional refusal to negotiate? In a letter to the health committee ahead of today’s hearing, Lem made clear its intention to break Nice: “As long as Nice remains constrained by its current approach to the technology appraisal process, and, ultimately, by the budgetary limits set by the Department of Health and Social Care, it is unlikely that the parties will arrive at an outcome that grants access to our treatments for CF patients in England.”

This echoes what Donald Trump has been threatening about any future UK/US trade deal. He accuses other countries of “freeloading” at America’s expense, promising to “put American patients first”.

True, the NHS and other countries with national health services do acquire drugs much more cheaply; Trump wants them to pay more so that Americans can pay less. Dillon explains the reason why the US pays more: their thousands of privatised, fragmented, insurance-based systems buy drugs in small batches haphazardly. Britain and other countries with unified health services use negotiating muscle to strike a good price as the single-payer for all patients.

US high costs, says Dillon, are also caused by “US drug companies spending billions and billions on advertising drugs directly to patients, in every TV ad break, which hugely inflates prices”. Britain bans advertising of prescription drugs, except to doctors.

The economies and efficiencies of the NHS are a political affront to Trump. Vertex is in the vanguard of trying to undo Nice’s fair rationing system, which is the practical and philosophical heart of a nationalised, universal health service.

Watch how in any trade deal Trump will demand open access to the whole of the NHS so that US companies can bid for any part of it. But that will never happen because expensive drugs and privatisation would be absolute deal-breakers for British voters, alongside forced importation of US food standards. No government would survive the fury such a deal would inevitably provoke. If there is to be no US trade deal, what exactly is Brexit for? Vertex is as good an emblem as you could find for the ugly American as seen through British eyes.

• Polly Toynbee is a Guardian columnist