Harry and Meghan could be stripped of their royal titles under legislation being proposed by a Tory MP.
Bob Seely suggested he could bring forward a private members' bill in the New Year that would see MPs vote on a resolution to give the Privy Council the power to downgrade the couple's royal status.
The Isle of Wight MP asked why Harry continues to use his title of Duke, while " at the same time trashes the institution of monarchy and his family" following the couple's new Netflix documentary.
"There is a political issue," Mr Seely said. "As well as trashing his family and monetising his misery for public consumption, he is also attacking some important institutions in this country."
He urged the Duke of Sussex to have a "sense of consistency" if he continues to attack the monarchy.
York Central MP Rachael Maskell has already got a bill going through Parliament to give the monarch new powers to remove titles, or a committee of Parliament to determine if a title should be taken away.
She has previously said that her constituents want the Duke of York to be stripped of his title.
Mr Seely's plan is to amend the royal 1917 Titles Deprivation Act, which stripped royal titles from those who supported Germany in the First World War.
It comes as Tory minister Guy Opperman suggested people should “boycott” the Sussex's bombshell new Netflix documentary.
Appearing on BBC's Question Time, Mr Opperman said: "I think they are clearly a very troubled couple, which I think anybody looking at them can say is a sad state of affairs.
"That having been said, I agree that they are utterly irrelevant to this country and the progress of this country and the royal family that we all, I believe, support."
Mr Opperman added: "I don't think it has a fundamental impact on the royal family.
"I certainly won't be watching it. I would urge everyone to boycott Netflix and make sure that we actually focus on the things that matter."
But he said the extent to which the couple's lives were "picked over" by the media when they were living in the UK was "unacceptable".
Downing Street declined to comment on his words but said it was up to the public whether they watch Netflix.
Asked if the PM backed stripping royal titles, he said: "I believe you are referring to a Private Members Bill which we do not support."
