The chancellor is refusing to publish an analysis of the likely economic damage from the new Brexit deal ahead of Saturday’s crunch vote, amid suspicions it would reveal a £130bn hit.

Senior MPs have condemned as “unacceptable” a failure to publish the information, when the Commons is being asked to make its most momentous decision in decades.

They suspect “the existing analysis stands” – pointing to Treasury data, last year, that said the limited free trade deal Mr Johnson now plans with the EU will strip 6.7 per cent from GDP over 15 years.

No 10 denies that and suggested a fresh analysis would be published, but not until after the Brexit agreement is put before MPs in the rush to seal the deal.

Hilary Benn, the chairman of the Commons Brexit committee, demanded the “fullest assessment available”, suggesting the new deal was “even worse for the economy than Theresa May’s”.

The scrapped deal pointed to the entire UK remaining in the EU’s customs territory, but Mr Johnson’s offers that benefit to Northern Ireland only.

Dominic Raab came under fire after describing it as a “cracking deal” for Northern Ireland because it will keep “frictionless access to the single market” – which the rest of the UK will lose.

Catherine McKinnell, the interim chairwoman of the Treasury Committee, also demanded an updated economic assessment, saying: “It is unacceptable that the committee has not received this information from HM Treasury.

“It appears to be an attempt to avoid scrutiny. If the chancellor does not provide the committee with an update, we can only assume that the existing analysis stands.”

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That analysis – published last year – predicted £130bn of lost growth by 2034 from a limited trade deal, which would leave people an average of £2,250 a year poorer.

But, quizzed on a visit to the United States, the chancellor Sajid Javid said: “There is no need for an impact assessment.”

Instead, he argued what was crucial was to end the uncertainty that has dogged the world’s fifth-biggest economy since voters decided to leave the EU in 2016.

“It is self-evident that what we have achieved in terms of this deal is the right way forward for the economy, much better than any alternative,” he claimed.

That is directly contradicted by the existing analysis, a detailed 83-page document published by the Treasury, the departments for Brexit, industry, environment and international trade and the Home Office.

It found a Canada-type free trade agreement would swipe 6.7 per cent from GDP, because of the new barriers to trade with the UK’s neighbours.

Even that modelling involved a heroic assumption that “successful” bilateral trade deals will be struck with 17 other countries, including the US, China and India.