Steve Baker, Tory Brexiter MP and chair of the eurosceptic European Research Group (ERG), has threatened to vote against a deal Boris Johnson could strike with the EU if it is “Brexit in name only”.

When asked if he was concerned about potentially losing the whip in such a scenario, Baker replied: “I’m not worried about it – what’s sauce for the goose is sauce for the gander.”

He told City A.M.: “I do not expect Boris to bring back a deal that is Brexit in name only. If he does I shall certainly vote against it, do or die, come what may.”

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Meanwhile, he said the Prime Minister was “absolutely right” to sack more than 20 Tory MPs who backed a move to block a no-deal Brexit, which is likely to become law tomorrow.

Baker said the 21 rebels – which include father of the House Ken Clarke, former chancellor Philip Hammond and former Tory leadership hopeful Rory Stewart – were MPs who “wanted to take from the government its power to govern”.

Baker admitted he had rebelled “many times” against Theresa May’s government when it tried – and failed – three times to get her withdrawal agreement through parliament, but said he had only done so on issues of policy.

He rejected remarks from Hammond that the Conservative party had been “taken over by unelected advisers, entryists and usurpers who are trying to turn it from a broad church into an extreme right-wing faction”.

“God bless Philip Hammond, but he is going off the rails,” he said. “He is making a fool of himself with these hysterical remarks.”

Baker said he was “especially disappointed by the contempt with which he [Hammond] is treating the Conservative party in its unity and capacity to function. As he will know personally, I have bent over backwards to keep our party together.”

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Last month fellow ERG member Mark Francois told ITV that he would vote against Johnson’s deal if it is similar to May’s withdrawal agreement.

Johnson has himself said the withdrawal agreement is “dead” and that the Irish backstop – the policy designed to prevent a hard border in Northern Ireland by keeping the UK in a temporary customs union with the EU – should be abolished.

However, Francois said he will still vote against any new deal, even if the backstop was removed.