The former Cabinet minister, who was Margaret Thatcher’s enforcer, warned dissident backbenchers they would “damage their country” in harrying the passage of the EU Withdrawal Bill.
The veteran peer berated them for risking an election that threatened to usher in “a Marxist government” under Labour’s Jeremy Corbyn.
Lord Tebbit made his blunt remarks amid the threat of fresh Westminster skirmishes when MPs continue their line-by-line scrutiny of the bill.
The bill will end EU law in the UK.
Battlelines have been drawn up over the move to enshrine the exit date of 11pm on March 29, 2019 in law.
More than a dozen Conservative MPs have threatened to oppose the plan, arguing it could tie the hands of negotiators.
Last night, a senior cabinet source said there was even a chance the Government would withdraw the date amendment.
But speaking to the Sunday Express, Lord Tebbit said: “There’s an enormous amount of posturing. “In the end these people have got to make up their minds whether they are going to defy the verdict of the referendum or whether they are going to fall into line.”
He added: “They may be thrown some sort of shreds to cover themselves so to speak, to save their dignity, but that’s all.
“The decision was made. Article 50 has been triggered – that means that we leave the EU on March 29, 2019. “All they can do is damage their country in the process.”
In a stark message to would-be mutineers, Lord Tebbit urged them to “stop trying to get an election at which we will get a Marxist government elected”.