CJohn Bercow, the spokesman for the heads of state, said he believes there is a "controversial case that the government has committed disrespect" because he has not fully published his Brexit legal advice.

The move followed a letter from DUP, Labor, SNP, Liberal Democrats, Greens and Plaid Cymru to Mr Bercow in which he called for a prosecution case to be opened, which could lead to sanctions against ministers, including the Attorney General, Geoffrey Cox, who led the MEPs had previously said Britain will indefinitely engage with the EU when it enters into force.

Mr. Cox told his critics in the Commons that it was time for them to "grow up and become real" about the lawyer, saying, "There's nothing …