A group of British MPs has urged U.S. Secretary of State Mike Pompeo not to allow anti-Islam activist Tommy Robinson into America.
Robinson, a founder and former member of the far-Right group the English Defence League, has been invited to speak at an event in Washington later this month.
He is understood to be waiting for authorisation under the U.S.'s ESTA system before embarking on the trip, which opponents fear could open up new sources of funding for his campaigns.
A cross-party group of MPs has now written to the Trump's administration's Mike Pompeo, head of the U.S. State department, insisting Robinson should not be allowed to use the trip to 'promote his violent and extremist agenda'.
The politicians say Robinson's previous bid to get into the U.S. using someone else's passport, for which he was jailed in 2013, should preclude him from going there again.
The letter states: 'We hope you agree that it would send a terrible signal if a convicted felon deemed inadmissible to the United States such as Yaxley-Lennon were allowed to travel to your country and speak before a prominent audience despite his conviction for previously entering the United States illegally.
'Clearly the gravity of his criminal serious record, his brazen violation of U.S. immigration law and the threat he poses to the American public will ensure that he isn't granted admission to the U.S.'
The letter is signed by Tory Michael Fabricant, Labour's Chris Bryant, Ian Austin and Luciana Berger and the Lib Dems' Tom Brake, among others.
Robinson, who is also planning a speaking tour of Australia, has previously claimed 'lies' are being spread about him to prevent him from travelling.
His profile around the world grew after he was jailed for endangering the trial of an Asian grooming gang by posting videos filmed outside court online. His conviction was later quashed.
Anti-extremism group Hope Not Hate say he is now trying to cash in on the notoriety the case brought him and will use any money raised to organise 'violent and divisive' demonstrations.
Robinson, real name Stephen Yaxley-Lennon, was freed from prison in August after three judges quashed a contempt of court finding made at Leeds Crown Court.
He was formally released from bail on Monday, but could face further legal action by the Attorney General.
He denies breaching the Contempt of Court Act and making a broadcast likely to seriously prejudice the trial, the Old Bailey has heard.
The Attorney General's Office has said all the material was being looked at 'afresh' before a decision was made on whether to refer Robinson to the High Court for contempt.
Setback for Robinson as he is banned from using PayPal
The MPs letter emerged a day after Robinson was banned from using PayPal to raise funds.
The 35-year-old said the online payments system told him he did not fit within its user guidelines and would never be able to use the platform again.
The company said it does not comment on individual accounts but added in a statement: 'We do not allow PayPal services to be used to promote hate, violence, or other forms of intolerance that is discriminatory.
'We do not take decisions like these lightly, and we work hard to be rigorous and fair-minded when reviewing PayPal accounts.'
The move comes after online petitions, demanding the firm stop processing payments for the activist, gathered thousands of signatures.
But Robinson, real name Stephen Yaxley-Lennon, who said he had been using the platform to collect donations to fight his legal battles, branded the ban as 'fascism'.
'They just don't like my opinion and want to silence me,' he told the Press Association.
'The Government and establishment can see I have public support, they can see I have the ability to fight back.'
Robinson said PayPal has also frozen 'a lot' of money that was in the account for 180 days.
PayPal said: 'Striking the necessary balance between upholding free expression and open dialogue and protecting principles of tolerance, diversity and respect for all people is a challenge that many companies are grappling with today.
'We work hard to achieve the right balance and to ensure that our decisions are values-driven and not political.'