The Government is being urged to ban a Lebanese journalist with links to militant group Hezbollah from entering Britain.
Ibrahim Moussawi has been invited to speak at a London university next month, but the Conservatives have written to Home Secretary Jacqui Smith urging her to keep him out of the UK.
Moussawi edits the newspaper Al-Intiqad, which is linked to Lebanese political and military organisation Hezbollah.
He previously worked for Hezbollah’s official TV station, Al-Manar, which has been criticised for its allegedly anti-Semitic output.
Moussawi, who was barred from entry to Ireland in 2007, has issued firm denials to accusations that he has made anti-Semitic or hateful comments.
Despite Tory opposition he was allowed to visit Britain to carry out public speaking engagements in December 2007 and in February last year.
Now he has been invited to speak at a course on political Islam at London’s School of Oriental and African Studies on March 25.
On its website the university describes him as an “expert on Hezbollah and Islamist political theory” and says he will talk about Hezbollah’s “history, strategy and ideology” and “current politics and prospects”.
The Conservatives said Mr Moussawi was a “known extremist” who had made “anti-Semitic and inflammatory” remarks, and called for him to be prevented from entering the UK.
Pauline Neville-Jones, the shadow security minister, wrote to Smith:
“In October last year you introduced what you described as ‘tough new measures’ to deny entry to extremists.
“These measures included ‘creating a presumption in favour of exclusion in respect of all those who have engaged in fostering, encouraging or spreading extremism and hatred’. Mr Moussawi has so engaged.
“In line with your ‘tough new measures’, I trust that if Mr Moussawi applies for entry, you will use your powers to exclude him.”
The dispute comes a fortnight after the Government banned far-right Dutch politician Geert Wilders from entering Britain to show his controversial 17-minute film Fitna in the House of Lords.
It is understood that the Home Office has so far not received a request for a visa from Mr Moussawi.
A Home Office spokesman said: “The Government opposes extremism in all its forms. We are determined to prevent individuals coming to the UK who want to spread extremism, or hatred in our communities.
“That was the driving force behind the tighter rules on exclusion for unacceptable behaviour that the Home Secretary announced on October 28 last year.
“Exclusion decisions are based on hard evidence not hearsay, and are targeted at those who seek to stir up tension and provoke others to violence regardless of their origins and beliefs.”