Labour’s plan to build 1.5m homes during this parliament is not achievable because of a severe skills shortage, an ageing workforce and Brexit, the head of Britain’s largest housebuilding company has said.

The government outlined on Thursday how it would achieve this goal. The proposals within the revised national planning policy framework (NPPF) include individual targets for each planning authority and new rules that will allow for housebuilding on poorer quality green-belt land.

The Barratt Redrow chief executive, David Thomas, when asked by the BBC if there were enough workers to build the extra homes promised by Keir Starmer and Angela Rayner, said: “The short answer is no.”

He added that the government would have to “revolutionise the market, revolutionise planning, revolutionise methods of production” to make their target achievable.

“They’re challenging targets. I think we have to recognise that this is a national crisis,” Thomas said.

The Home Builders Federation (HBF) echoed Thomas’ sentiments.

The HBF told the BBC the UK “does not have a sufficient talent pipeline” of builders to meet Labour’s goal, citing recruitment constraints with poor perception and lack of training within schools, not enough apprenticeships, and the cost of taking on apprentices.

The industry body said the sector had not “attracted” enough recruits in recent years, saying a quarter of tradespeople were aged over 50.

The concerns from within the construction industry have dampened prospects for the prime minister’s construction targets, after he said on 5 December his government would “absolutely” push development through.

Starmer said he wanted to “get the balance right with nature and the environment” but that “a human being wanting to have a house” had to be the top priority.

As well as its commitment to build 1.5m homes, the Labour government intends to make decisions on 150 major infrastructure projects during this parliament.

The updated NPPF commits to a “brownfield first” strategy, with disused sites that have already been developed in the past prioritised for new buildings.

The default answer when a developer seeks to build on brownfield sites will be yes, but the government says these sites will not be enough for the number of homes needed.

Councils will be ordered to review their green-belt boundaries by identifying lower-quality “grey belt” land that could be built on.

The framework defines the grey belt for the first time as green-belt land that “does not strongly contribute to green-belt purposes”. Those purposes include limiting urban sprawl, stopping neighbouring towns merging into each other, and preserving the special character of historic towns.

Safeguarding the countryside from encroachment and assisting in urban regeneration are no longer included as green-belt purposes.

“For years, we have had not enough houses being built. That means that individuals and families don’t have the security that they want,” Starmer said during a visit to a construction site in Cambridge.

“We are determined to break through that, to do what’s necessary.”

More specific guidance on how local authorities can assess their green-belt land is due in January.

The government announced £100m of additional cash for councils, along with 300 additional planning officers, to speed up decision-making processes.