Brexit minister Steve Baker has claimed every single economic forecast produced by the civil service is “wrong”.

The government is under pressure to publish in full a leaked internal analysis which concluded Britain would be worse off whatever Brexit deal is struck with Brussels.

Speaking in the Commons on Tuesday, former Labour shadow chancellor Chris Leslie accused Baker of a “deeply irresponsible” decision to withhold the study. “This is cover-up pure and simple and it stinks,” he said.

Baker told MPs the leak to BuzzFeed was an “attempt to undermine our exit form the EU”.

He said to government analysis of various Brexit outcomes risked “exposing our negotiating position”.

And he pledged an “appropriate” economic analysis would be provided to MPs after talks had been completed and MPs were preparing to vote on the proposed deal.

However Sir Keir Starmer, the shadow Brexit secretary, said this was “not good enough” and accused ministers of “piling absurdity upon absurdity”.

In an attempt to rubbish the document, which said even if the UK was able to negotiate a comprehensive free trade agreement growth would be down 5% over the next 15 years, Baker said forecasts were never correct.

“I am not able to name an accurate forecast and I think they are always wrong and wrong for good reasons,” he said.

However despite claiming all forecasts were wrong, Baker said the leaked study showed economic growth was still predicted “in all scenarios” of Brexit.

Theresa May held a Cabinet meeting this morning following the leak.

Downing Street spokesman said: “At the beginning of cabinet the prime minister noted media coverage of a report purporting to show the economic impact of Britain leaving the EU.

“The prime minsiter said this was initial work not approved by ministers which only considers off-the-shelf scenarios. No analysis was made of the bespoke arrangement we seek as a matter of government policy as set out in the Florence speech.”