Mandelson says Brexit ministers should be sacked

His comments came as it emerged Leave-supporting Cabinet ministers could be forced to use the Freedom of Information (FoI) Act to gain access to official documents from their own departments relating to the EU referendum.

The top civil servant in the department of Leave campaigner and Northern Ireland Secretary Theresa Villiers told MPs that, under the terms of the guidance issued by Cabinet Secretary Sir Jeremy Heywood, the minister might have to use a FoI request or a parliamentary question to obtain information produced by her own staff.

Intervening in the row over the contents of “Chris Grayling’s in-tray”, Lord Mandelson said: “Frankly, I think, these complaining ministers are lucky. Usually when members of a government go against ministerial collective responsibility and the will of the Cabinet, they receive one paper - and that’s their P45. “So I think they have got off rather lightly and they should stop whinging.”

Lord Mandelson also singled out Boris Johnson for criticism following the London mayor’s comparison of himself to James Bond, standing up for Britain against the forces of Brussels.

The Labour peer said: “It would be thoroughly reckless for Britain to sacrifice the settled network of trade advantages and preferences that we have built up over decades through our membership of the EU, all for the thrill of a daredevil race around the international circuit in our own Aston Martin as Boris had it over the weekend.”

Lord Mandelson warned the UK would “pay an economic price” for leaving the EU and negotiations with former partners in Brussels would not be easy.

He asked: “Why should those who have just divorced us give us back the keys to the marital home as if nothing has changed?”