The government’s official Brexit impact forecasts should never have been kept secret, according to its own budget watchdog.
Ministers should have planned to publish the controversial documents from the outset, said Robert Chote, who is chairman of the Office for Budget Responsibility.
The papers, drawn up by civil servants in David Davis's Department for Exiting the EU, suggested that Brexit will leave Britain worse-off under any likely scenario.
Growth will be depressed by five per cent over the next 15 years if the UK gets a comprehensive trade agreement or eight per cent if it leaves without a deal, the forecasts by economists predicted.
"I think it's fair to say that there's clearly a logical case for having a good study done of the economic impact of the different models or the different potential outcomes that the Government is thinking of looking at," said Mr Chote.
"And I think there's also a case for saying that in the current environment... if you do a lot of that work and you circulate it around government it's not entirely surprising that it leaks and gets into the public domain.
"In an ideal world, you would have embarked on this exercise in the hope and expectation that you end up with a published project or outcome that can be shared with the public in general as well as within government."
The papers, which were leaked to website BuzzFeed News, sparked fury among Conservative Brexiteers. Jacob Rees-Mogg, who is chair of the pro-Brexit European Research Group of Tory MPs, described their findings as "highly speculative".
Prime Minister Theresa May said the analysis was incomplete and had not been signed off by ministers.
But ministers were forced into agreeing to release the documents after coming under parliamentary pressure from Labour and critics on the Tory benches.
