Anne-Marie Trevelyan hit out at Whitehall mandarins for leaking a report warning about the dangers of a ‘no-deal’ Brexit.
The doom-mongering document claimed the UK could run out of medicines, food and fuel after leaving the bloc.
But Mrs Trevelyan, the MP for Berwick upon Tweed, mocked the suggestion that leaving the EU would spark ‘Armageddon’.
The anti-EU backbencher said: “A civil servant’s job is to give advice to ministers, who then make decisions.
“There are some civil servants who I imagine, at a personal level, are perhaps not thrilled about the Brexit direction of travel.
“But it’s not their job to leak, and I hope that anyone who’s found to be leaking is sacked, because that’s not how it should be done.”
The report, leaked last month, was reportedly branded the ‘Doomsday Brexit scenario’ by Whitehall officials.
It warned that if Theresa May fails to strike a deal with the EU, the worst-case scenario would be ‘Armageddon’.
The port of Dover would “collapse on day one” and hospitals would run out of medicine within two weeks, the shocking dossier added.
But Mrs Trevelyan played down these warnings, saying the UK’s exit from the EU next March is “is not an Armageddon situation”.
Speaking on the Brexit Breakdown podcast by the UK in a Changing Europe think-tank, she said: “Armageddon could come in a number of ways.
“I would hope the civil service is prepared for any number of Armageddon situations, such as a chemical attack.
“Our civil service and public servants have the duty to be prepared for the unexpected.
“But the process of Brexit and leaving the EU, a legal set of treaties, is not an Armageddon situation.
“The suggestion in this report that we are going to run out food and medicine misses the point.
“It wrongly implies that we are closing our borders, that no one else would be able to provide those things.
“Preparedness is the key. Hospitals, water companies and electricity companies all have preparedness plans.”
A spokesman for Brexit Secretary David Davis also dismissed the dire warnings from Whitehall, saying they were “completely false”.
Influential Tory backbencher Jacob Rees-Mogg, head of the European Research Group, said the document was “Project Fear on speed”.
He added: “It is a fallacy that countries will unilaterally decide to stop selling you their goods.
“The idea that food will not get through at Dover is entirely wrong.
“We would be free to import food, medicines, fuel as we wished and the EU could only stop this if it were to impose sanctions, which is not a credible thought.”