A Brexit minister has been forced to apologise for incorrectly stating in the Lords that the Supreme Court had ruled Article 50 was irreversible.

Lord Callanan, who joined David Davis’s department last month, told peers his comments were “incorrect” and “a misunderstanding of the question on my part”.

He had been asked by a Conservative colleague whether he could confirm that the judgement of the Supreme Court in the case brought by Gina Miller had in “precise terms” ruled on the revocability of Article 50.

"I can confirm that," said Lord Callanan. "It is also stated by the European Commission that Article 50, once invoked, is irrevocable unless there is political agreement on it.”

While the UK’s highest court had ruled that Theresa May was required to seek approval to trigger the mechanism - kick–starting Britain’s departure from the EU – it had not made a judgement on whether the process could be reversed.

Correcting his comments seven days later the Brexit minister conceded that the Supreme Court “did not opine on the revocability of Article 50”.

He continued: “I would like to take this further opportunity to clarify the Government’s understanding on the Supreme Court case.

“To reiterate, for the avoidance of any doubt, the Supreme Court proceeded in the Miller case on the basis that Article 50 would not be revoked but did not rule on the legal position regarding its revocability.

“Once again, I am grateful to this House for the opportunity to make a statement. I recognise that my comments have caused confusion and I apologise to the House.”

Baroness Hayter, Labour’s Shadow Brexit minister in the Lords said: “I welcome Lord Callanan’s statement but in future he shouldn’t allow his well-known, hard Brexit bias to cloud his ministerial responsibility to give accurate advice to Parliament.”

James McGrory, the executive director of Open Britain, added: “That a Minister should be forced to clarify his comments for a second time shows both how wrong this Government’s interpretation of the revocability of Article 50 is and how determined they are that the public should be left in the dark about it.

“The truth, as the author of Article 50 has confirmed, is that the Government can withdraw its notification and stop the process at any time. Brexit does not need to mean Brexit if the British people don’t want it to. This process is not inevitable unless we want it to be.“

Following his comments last week the Labour peer Lord Adonis, said Lord Callanan’s comments in the upper chamber amounted to a “serious breach of ministerial code”.

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He added: “I have tabled Lords motion referring Brexit minister Lord Callanan to privileges committee for falsely claiming Supreme Court said Article 50 notice could be withdrawn & refusing to correct this.”

The row comes after the former diplomat Lord Kerr, the legal expert who wrote Article 50, said during a speech that the country “still has a free choice about whether to proceed” with Brexit.

“As new facts emerge, people are entitled to take a different view. And there’s nothing in Article 50 to stop them,” he said.