The remarks came as senior security sources told The Mail on Sunday Hezbollah could be preparing reprisal attacks against Jewish and Israeli targets in British cities.

Leading London-based Islamic rights activist Massoud Shadjareh said British Muslims could provide Hezbollah with 'financial, logistical and informational support' to attack Israeli installations. His Islamic Human Rights Commission called for the occupation of Israel and 'regime change' by Hezbollah on self-defence grounds.

Mr Shadjareh said his organisation was attempting to combat the 'rhetoric coming from the United States and Britain regarding the situation in the Middle East'. But the US State Department lists Hezbollah as a terror group and its "External Security Organisation' - its terrorist wing - is banned by UK anti-terror laws. Mr Shadjareh said: "We are not supporting or opposing Hezbollah or anybody else." However, The Mail on Sunday obtained a photograph of him wrapped in a Hezbollah flag at a rally in Trafalgar Square last year. He said: "The wearing of the Hezbollah flag is neither uncommon nor controversial among human rights activists."

Whitehall security sources last night confirmed MI5 and anti-terrorist police were investigating threats to Jewish and Israeli targets in the UK. They fear Hezbollah may resort to a renewed international terror campaign. In July 1994 the Israeli Embassy in London was car-bombed by two Palestinians linked to Hezbollah. Fourteen people were injured.

Foreign Secretary Margaret Beckett told the Commons last week that 'there are indeed concerns' about Iran-backed terrorists attacking the UK. She said: "All I can say is our security services and police are doing everything possible to...ensure that we keep British people as safe as we can."

Tory Homeland Security spokesman Patrick Mercer said: "There is little doubt that we are in danger from Hezbollah. I trust that the Government are more alive to this threat than they have been to other Islamist fundamentalist threats."