It would be “colossally stupid” to trigger Article 16 and suspend the Northern Ireland Brexit agreement, John Major has warned.
Speaking on Saturday the former Tory prime minister branded the policy – thought to be under consideration by Boris Johnson – “absurd”.
It comes after Lord Frost, the UK’s Brexit negotiator, said the drastic course of action was “very much on the table and has been since July”.
The EU has warned of “serious consequences” if the protocol is suspended.
The agreement was designed to stop a hard border from appearing between Northern Ireland and the Republic, but also puts controls on trade between Britain and the EU.
The UK has taken issue with the controls it signed up to and says it wants the protocol to be changed. The EU has presented proposals – but the UK says they do not go far enough.
Some reports speculative reports suggest Mr Johnson wants to trigger Article 16 – the agreed mechanism to suspend it – after the Cop26 climate summit is over and Britain is no longer in the spotlight.
“I think it would be colossally stupid to do that,” Sir John, who led the government from 1990 to 1997, told BBC Radio 4’s Today programme.
“To use Article 16, to suspended parts of the protocol, would be absurd. This protocol is being denounced week after week by Lord Frost and the prime minister.
“Who negotiated the wretched protocol? Lord Frost and the prime minister. They negotiated it, they signed it, they now wish to break it.”
The ex-Tory leader, who opposed Brexit, was speaking after Northern Irish business groups and nationalists warned against the approach.
Aodhán Connolly, director of the Northern Ireland Retail Consortium, told The Independent that suspending the protocol “plunges us into more instability, more uncertainty, more negotiations”. Meanwhile SDLP Brexit spokesperson Matthew O’Toole, a member of the Stormont assembly, warned that Boris Johnson and Lord Frost “seem determined to escalate and increase confrontation in a way that people here do not want” – branding the approach “a chilling insight into how little they actually care about the region”.
Some unionists and loyalists have however called for the protocol to be ended. DUP leader Jeffrey Donaldson said he expected decisive action to be taken by the end of November.
After a meeting between Maros Sefcovic and Lord Frost on Friday, the UK’s chief negotiator said progress had been “limited”.
Mr Sefcovic, the EU’s Brexit chief and Commission vice president, said triggering Article 16 would “lead to instability and unpredictability”.
Speaking on Saturday Sir John, who faced down Eurosceptic rebels while he was prime minister, added: “At the moment, we are negotiating over the protocol with all the subtlety of a brick.
“What is happening week after week is that Lord Frost goes into the negotiations, he gives away nothing, he takes something from the European Union, he goes away, blames them for the fact that nothing at all has happened.”
Sir John said he suspected Article 16 would be triggered after the United Nations Cop26 climate summit being hosted by the UK in Glasgow has concluded.
“This is a very difficult and dangerous road to go down. It’s not just a question of trade difficulties.
“It could, we’ve seen what’s happened in Northern Ireland before, it could become much worse. They should be very, very careful about this.
“This is silly politics to placate a few extreme Brexiteers, and the price will be paid by businesses, people in Northern Ireland and the reputation of the United Kingdom.”
Talks between Lord Frost’s and Mr Sefcovic’s negotiating teams are expected to resume next week.
