European Union diplomats say talks to finalise the implementation deal could begin as early as next week with negotiators aiming to reach a swift deal.
The document went even further, showing how nearly every sector of the economy would be affected by the three scenarios - chemicals, clothing, manufacturing, food and drink, and cars and retail are the hardest hit.
However, the Prime Minister's party is firmly divided into two camps for what happens after this transition phase.
A spokesman for the prime minister said the paper leaked to BuzzFeed News was only an initial assessment that had not considered the government's preferred goal of a bespoke future relationship with the European Union after leaving.
The analysis, titled "EU Exit Analysis - Cross Whitehall Briefing" and dated January 2018, looked at three possible scenarios: a no-deal scenario, in which the United Kingdom would revert to World Trade Organization (WTO) rules, a comprehensive free-trade deal with the EU and a continued single-market access through a European Economic Area membership.
Britain's Brexit Minister David Davis said yesterday that after the transition period, he expects some countries to want to renegotiate free trade deals made by the EU.
"For months, Theresa May's Government have refused to produce any detailed analysis of the potential impact of various Brexit scenarios; now we know why they have so desperately engaged in a cover-up".
Even under the "softest" option of remaining inside the European Economic Area but leaving the EU, growth would be 2% lower than staying in.
Matthew Pennycook, shadow Brexit minister, said: "Labour has made clear since the referendum that Tory Ministers can not withhold vital information from Parliament and the public about the impact of different Brexit scenarios on jobs and the economy. No one voted to make themselves or their families worse off".
A government spokesperson has told the Guardian: "We have already set out that the government is undertaking a wide range of ongoing analysis in support of our European Union exit negotiations and preparations".
HuffPost UK has learned some MPs are so furious with the behaviour of their colleagues the Tory whips have been asked to take action against the dissenters - who appear to be seemingly untouchable as they tour TV studios calling for the Chancellor to be sacked or questioning the Government's Brexit strategy.
"The Prime Minister must now agree to publish this analysis in full and any other analyses which they are concealing from the people of these islands".
At the same time, the source said that the report includes "a significant number of caveats and is hugely dependent on a wide range of assumptions".
"We love your country", Trump said in comments carried by The Hill.
Amid fears among some Brexiteers that the Government is heading for a "soft" break, retaining numerous current elements of Britain's relationship with the EU, Mr Rees-Mogg said the Prime Minister needed to spell out what sort of deal she was looking for.