A Government Brexiteer has insisted Britain "must" leave the EU's internal market, as ministers jockey for position ahead of a crunch Cabinet summit at Chequers next week.
Brexit minister Steve Baker's comments will be widely seen as a swipe at Business Secretary Greg Clark, who issued a plea on Tuesday for the Government to listen to business warnings of disruption to trade.
The public remarks reflect an intense tussle behind the scenes ahead of the meeting at Theresa May's country residence at which the Prime Minister aims to secure Cabinet backing for her vision of Britain's future relations with the EU.
The plans, covering issues such as trade and security, are due to be set out in a long-awaited white paper next month which is expected to outline in detail how the PM envisages Britain engaging in future with the EU's single market and customs union.
In response to speculation that Mrs May could seek continued membership of the single market for goods, Mr Baker tweeted: "Government policy is, and must remain, to leave the EU's internal market as we leave the EU."
Jacob Rees-Mogg, chairman of the influential European Research Group of pro-Brexit Tories, accused Chancellor Philip Hammond of working with business leaders to raise concerns about leaving the EU.
"I think there is co-operation between the Remainers in the Cabinet and some businesses, some of the more politicised businesses," Mr Rees-Mogg told Sky News.
Asked who in the Cabinet he meant, Mr Rees-Mogg replied: "Oh, the Chancellor. Boris Johnson was quite right when he said the Treasury is the beating heart of Remain, that's obvious."
The Chequers summit takes place against the backdrop of increasingly public warnings from multinational firms such as Airbus and BMW that they will have to rethink their operations in the UK in the case of a "hard Brexit".
In a pointed message to Cabinet colleagues, Mr Clark said that the Government should listen to the advice of firms which had "actual experience" of trading with the European Union rather than a "theoretical view of what the world might be like".
He insisted the Government was working to secure a Brexit deal that does not involve "customs frictions", maintains a role for the UK in standard-setting bodies and continues to allow foreign talent to come to Britain.
Earlier, ministers Jeremy Hunt and Liam Fox publicly rounded on Airbus and other firms questioning the Government's handling of Brexit negotiations, while Boris Johnson reportedly responded to the row by saying: "F*** business."
The Foreign Secretary appeared to confirm reports of the remark, telling the House of Commons: "It may be that I have from time to time expressed scepticism about some of the views of those who profess to speak up for business."
The Chequers summit follows a meeting of EU leaders in Brussels on Thursday and Friday this week, at which Brexit is not expected to be high on the agenda.