LONDON, Feb. 7 (Xinhua) -- Every region of Britain would be affected in the case of three possible Brexit scenarios, with London the least hit, a secret impact analysis revealed Wednesday.

A group of MPs were allowed to study the highly sensitive documents Wednesday behind closed doors in the House of Commons library.

The documents assessed the possible economic impact of Britain leaving the European Union under three potential economic scenarios, a comprehensive free trade deal, single market access and no deal at all.

England's North East Region, centered around Newcastle and Sunderland, would come off worse in all three scenarios, while London would be least hit in any of the three outcomes, the papers revealed.

Downing Street reacted Wednesday night saying the papers did not cover all outcomes.

Extracts from the papers were leaked last week by the internet site Buzzfeed, prompting calls by politicians for the government to release the documents.

Instead a compromise was reached allowing some MPs to study the papers in private on a confidential basis.

In north-east England economic growth would be 3 percent lower if Britain stayed in the single market, 11 percent with a trade deal and a 16 percent fall with no trade deal compared with staying in the EU. In the same three scenarios London's economy would suffer the least, falling by 1 percent, 2 percent and 2.5 percent respectively.

The economic impact on Britain as a whole would see reductions under the three possible outcomes of 2 percent, 5 percent and 8 percent respectively.

The Guardian newspaper Wednesday night said their analysis showed a no-deal Brexit would blow 111 billion U.S. dollars hole in the public finances. Their report said the North East and West Midlands, where leave voters dominated the 2016 in-out referendum, would be worst affected.

Paul Blomfield, Shadow Brexit Minister for the main opposition Labour Party, said: "These figures are further evidence of why the Conservatives must rethink their reckless approach to the Brexit negotiations.

"The final Brexit deal with the European Union must work for every region and nation of the UK, protecting people's jobs and local economies. Theresa May should stop listening to the extreme Brexiteers sat around the Cabinet table and start putting the country's interests first."

Tom Brake, Brexit spokesman for the minority Liberal Democrats said: "This is a damning outlook for Britain. The Conservatives are putting everything on the line because they do not care about the lives and livelihoods of the people of the UK. They are still keeping no deal on the table despite how crippling it would be to the regional economy. People did not vote to make themselves poorer."

A government spokesman said: "This document does not represent government policy and does not consider the outcome we are seeking in the negotiations.

"As ministers clearly set out this is provisional internal analysis, part of a broad ongoing program of analysis, and further work is in progress.

"We are seeking an unprecedented, comprehensive and ambitious economic partnership - one that works for all parts of the UK. We are not expecting a no deal scenario."

Earlier Theresa May, speaking at Prime Minister's Question Time in the Commons, assured MPs that Britain will be robust in its arguments with the EU.

"As I have said right from the very beginning, we will hear noises off and all sorts of things being said about positions, but what matters is the position that we take in the negotiations as we sit down to negotiate the best deal. We have shown that we can do that."