The British people should be offered a second referendum on the final Brexit deal reached with the European Union, the former head of the civil service has said.

Lord Butler, a crossbencher who ran the civil service for a decade from 1988 to 1998, said a second vote was necessary for “establishing the up-to-date view of the British electorate” after it became clear what Brexit would actually mean.

The peer, who was also private secretary to five different prime ministers, asked the Government front bench whether it regarded “the views of the British people on the outcome of our negotiations as irrelevant tour departure”.

“We may ask our partners for things that they may feel unable to give and they may ask of us things that we are unwilling to give – like continuing large subventions to the EU budget,” he told the House of Lords.

“Is the outcome of last June’s referendum to be interpreted as meaning that a majority of the United Kingdom want to leave the EU whatever the terms? The Government clearly thinks so. On a matter of this importance has not the Government a duty to be sure before our departure becomes final?

“My Lords, one has to ask why those who base their arguments for Brexit on the will of the people are now opposed to consulting the people on the outcome of the negotiations. One has to suspect that they fear they will get a different answer. But if so, we ought to know.”

He made the comments on the second day of the House of Lords debate about the Government’s bill to trigger Article 50.

Yesterday other former senior mandarins in the upper house weighed in on Brexit. Lord Macpherson, former Treasury permanent secretary, and Gus O’Donnell, former head of the civil service suggested they could vote for dissenting amendments to the Article 50 Bill.

Liberal Democrat home affairs spokesperson Lord Paddick agreed with Lord Butler, arguing that "the British people did not know the full consequences of leaving the EU at the time of the referendum and they did not therefore make an informed choice”.

The Lib Dem added: “They are entitled to a vote on the final deal."

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Some peers rejected the idea of a second referendum, however. Baroness Neville-Jones, a Conservative peers, said: “Frankly I think we can rely on the normal electoral processes of this country kicking in to deliver a verdict on what happens next. I think our system will certainly cope with whatever outcome the negotiations delivers.”