The Prime Minister addressed MPs in the House of Commons, giving them an update on the latest state of Brexit negotiations having agreed on a deal with the European Union allowing trade talks to begin.
Given his turn to ask a question, Mr Umunna suggested senior civil servants had been asked to not put in writing any research into Brexit’s potential impact on various sectors.
The MP for Streatham asked the Prime Minister if there was a “cover-up” of these so-called impact reports.
He said: “Mr Speaker, senior civil servants across Whitehall have reportedly been instructed from here on not to commit into writing any evalution they make into the impact of Brexit on this industry sectors.
“Is this true, and if so, why the cover-up?”
The Prime Minister leapt to her feet to deliver her one-word slap down of the Labour MP.
Responding to Mr Umunna, Mrs May blasted: “No!”
Other shouts from around the Commons can be heard, declaring the Labour MP’s suggestion “rubbish”.
Brexit Secretary David Davis was forced to release over 850 pages of analysis on the impact of the UK’s EU divorce on certain sectors after a parliamentary vote.
Parliamentarians criticised the Brexiteer for the “ridiculous amount of security” surrounding the documents.
Another described the collection of documents as “two lever-arch files for 80 per cent of the economy”.
Brexit committee member Stephen Kinnock accused Mr Davis of disrespecting Parliament.
The Labour MP said: “He has handed over a tome the size of War and Peace and expects committee staff to photocopy it for members of the committee to read.
“The whole thing is childish. He is treating Parliament like children and, by extension, the British public like children.”
He added: “He is sailing very close to being held in contempt of Parliament – and he has certainly treated Parliament with contempt.”