Theresa May will press on with efforts to secure a revised Brexit deal, despite another Commons defeat, and will return to Brussels “within days”.

MPs voted against a motion endorsing the government’s strategy by 303 to 258, with 66 Tory MPs abstaining.

Steve Baker, of the Conservative backbench European Research Group, which led the rebellion, called it a “storm in a teacup”.

Business minister Richard Harrington accused the ERG of “treachery”.

He told The House magazine: “I read that [former UKIP leader] Nigel Farage is setting up a new party called ‘Brexit’ and, if I were them, I’d be looking at that – that seems to reflect their views more than the Conservative Party does.”

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The latest government defeat has no legal force and Commons Leader Andrea Leadsom told BBC political correspondent Iain Watson that Mrs May would go back to Brussels in the coming days to continue negotiations.

She told BBC Radio 4’s Today programme the loss represented “more of a hiccup than the disaster that is being reported”, insisting: “The prime minister carries on.

“She will continue to seek those legally binding changes to the backstop that will enable Parliament to support our deal.”

Mrs Leadsom blamed Labour for “playing politics” to defeat the government.

Mr Baker, the ERG’s deputy chairman, told Today he was “standing up for what the majority of the people voted for”, while still “making enormous compromises”.

And despite the government defeat, he argued: “It’s still very clear that there is a majority in the House of Commons for a deal which replaces the backstop with alternative arrangements. The European Union should understand that.

“But they should also understand that there are those of us unwilling to vote to take a no-deal off the table.”

Former Attorney General Dominic Grieve accused the Conservative Eurosceptics of being “completely cavalier about the risks” of leaving the EU without a formal withdrawal agreement, which many MPs fear would lead to chaos at ports and massive disruption to business.

And he suggested a dozen or more ministers – including six in the cabinet – might resign if the prime minister refused to extend Brexit talks beyond 29 March, when the UK is due to leave the EU.

“My understanding is that many of them have made representations directly to the prime minister indicating their concern and telling the prime minister that if by the end of February there is no deal that has been got through the Commons, we ought to extend,” he said.

“There is, I think, an overwhelming number of members of Parliament who believe that a no-deal Brexit would be catastrophic and they are looking to the government and saying to the prime minister: ‘Look, you don’t have a deal you can get through the Commons. We can’t crash out, therefore you’ve got to go and extend Article 50’, which I think our EU partners will do for us.”