A row has broken out between Downing Street and senior Eurosceptics over claims Theresa May’s aides told Boris Johnson and Michael Gove that the key concession used to seal Friday’s deal with Europe was “meaningless” and “not binding”.

A senior Eurosceptic with knowledge of the discussions involving Cabinet ministers, including Mr Johnson and Mr Gove, told The Telegraph that No 10 had said a commitment to “full alignment” between the UK and the EU “doesn’t mean anything in EU law”.

A separate source confirmed that a specific Cabinet minister had been told by No 10 aides that the provision was “meaningless” and was simply included to secure Ireland’s approval for the document.

The claims are likely to infuriate the Irish government and threaten to unravel the apparent Cabinet consensus over the deal ahead of the key meeting of the European Council this week, at which EU leaders will be asked to confirm that negotiations can now proceed to trade talks.

They also come at a time insiders admit that relations with Eurosceptics are “delicate”, and that the Government is separately braced for rows with pro-Europe MPs over the withdrawal legislation on Tuesday.

On Saturday night, a Downing Street spokesman said: “We do not recognise this account of conversations.”