Commons will be told to strip Harry and Meghan of their Royal titles 'after the latest instalment of the couple's feud with the rest of the Royal Family'

Parliament could consider the 'nuclear option' of stripping Harry and Meghan of their royal titles under bombshell legislation to be proposed this week.

Conservative MP Bob Seely is putting forward a Bill that could deny the couple their Duke and Duchess standing as the Royal Family becomes increasingly engulfed in the 'racism' row fuelled by the pair's unofficial 'mouthpiece'.

The Isle of Wight MP wants to adapt laws originally passed in the First World War to deny enemy German nobles their British titles. His Bill would force the Commons to consider turning Harry and Meghan into plain Mr and Mrs Sussex at a time when the couple are under mounting pressure to break their silence over incendiary claims made by author Omid Scobie.

His new book Endgame has reignited a race row when a Dutch translation named the King and Kate Middleton as the senior royals alleged to have speculated about the skin colour of Prince Archie.

Mr Seely said he had to act because of the attempt to use race to smear the Royal Family, which he called 'poisonously insidious'. 

Writing in The Mail on Sunday, Mr Seely said that while sources close to the Sussexes have stressed Harry and Meghan are not behind claims made in Scobie's book 'I suspect that few people believe such denials'.

The politician, a member of the Commons' Foreign Affairs Committee, adds: 'Of all the damaging insults to throw, 'racism' is the most poisonously insidious, guaranteed to leave a whiff of stigma and impossible to prove when false. It is the catch-all slur of the modern era.'

He is applying for his Titles Deprivation 1917 Amendment Bill to be listed on the Commons' Order Paper next week. It would resurrect the wartime powers by removing references to 'enemies' and 'present war'. He has cleared the wording with Parliament's Table Office, which oversees draft legislation.

Politicians normally steer clear of royal controversies, but the incendiary nature of the 'racism' claims has attracted rare levels of condemnation. Tom Tugendhat, the Security Minister, has praised the 'dignity' of the King and the Princess of Wales, and labelled the claims 'rumour and scuttlebutt'.

Harry and Meghan can no longer use His and Her Royal Highness under the 2020 deal in which they gave up official Royal duties. A Mail on Sunday poll this year found that 51 per cent of people think they should have their Duke and Duchess titles revoked too.

The King is expected to consult Prince William this week to discuss their response to the storm after Buckingham Palace said it is 'considering all options' when it comes to a response.

But it is understood that a formal meeting is not yet in the diary. A Royal household source told this newspaper: 'Undoubtedly they will meet to discuss how best to approach and react to the fallout from the rather tiresome Scobie affair.'

The royal race row first erupted more than two years ago, when the Sussexes told talk show host Oprah Winfrey that a member of the Royal Family had remarked on their son's skin colour before he was born.

The English edition of Scobie's book says Meghan mentioned who was alleged to have made the remarks in a letter she sent to Charles, but did not name names – however, the King and Kate were identified in the Dutch version.

Mr Scobie told BBC's Newsnight that he was 'hurt' and 'frustrated' by the week's events, but added: 'It's not for me to apologise because I still want to know what's happened.'

The Daily Mail reported yesterday that Buckingham Palace has been investigating who could have seen the letter from its end – likely to be just a 'tiny handful' of people. There is said to be 'extreme confidence' the leak didn't come from them.

The Sussexes have not commented publicly but a source close to Meghan told the Daily Telegraph 'it was not leaked to Mr Scobie by anyone in her camp'.

Meanwhile, Ms Markle's estranged father Thomas has waded into the controversy,

The 79-year-old – who fell out with his daughter after details of a letter she wrote to him were leaked by her friends – said: 'Here we have another letter from my daughter which has somehow made it into the public domain. Another letter? Again?

'The fact Harry and Meghan have not publicly distanced themselves from this strikes me as unusual.'

Meghan sued The Mail on Sunday after this newspaper published excerpts of the letter to her father.

Mr Seely's draft legislation is formally titled 'a Bill to amend [the Act] to deprive in certain circumstances Princes of their British Dignities and Titles'. The original 1917 Act allowed the Privy Council to make a report about British nobles suspected of aiding the enemy.

If neither the Commons nor the Lords tabled a motion opposing it within 40 days, the report would be presented to the Monarch and the person concerned would lose their title.