A Welsh peer who likened Theresa May's approach to Brexit to the Nazi takeover of Germany in 1933 has been urged to withdraw his "disgusting" remarks.
Lord Roberts of Llandudno claimed she was trying to undermine the role of Parliament as Adolf Hitler did when he seized power with his Enabling Bill.
Former Conservative minister Robert Halfon told MPs he found the comments "absolutely disgusting and shameful".
Speaker John Bercow said he had no role to police comments made in the Lords.
The Liberal Democrat peer made his comments as the House of Lords debated the EU Withdrawal Bill on Monday.
Lord Roberts criticised Mrs May's "reluctance" to allow parliamentary involvement in Brexit negotiations as she wanted the UK Government "to be in charge".
He said his mind "went back to Berlin in March 1933" when the German Reichstag (Parliament) passed an Enabling Bill which "transferred democratic rights of the parliament into the hands of one man".
"That was the Chancellor, and his name was Adolf Hitler," Lord Roberts added.
"Perhaps I'm seeing threats that do not exist, but they are there, they are possible."
'Trivialisation of evil'
Mr Halfon denounced the Welsh peer's comments when he spoke in the Commons on Tuesday.
"As someone who is Jewish, and someone who is very proud of our Parliament, I find these remarks absolutely disgusting and shameful," he told MPs.
"It's shameful for our country, it's shameful for our Parliament and completely unacceptable."
He asked the speaker if the Commons could send a message to Lord Roberts that "this trivialisation of evil is unacceptable and he should withdraw those remarks".
Mr Bercow suggested Mr Halfon write to Lord Roberts himself, saying: "The Speaker of this House has no role in policing or overseeing utterances in the other place and I don't think it is for me formally to take the matter forward.
However, the speaker added: "I think we should always speak with great care and sensitivity in either House."