The government spent more than £20,000 of taxpayers’ money sending civil servants on a course at which Hizbollah’s media relations officer was due to be a keynote speaker. In the event, Ibrahim Moussawi was barred from entering Britain by the Home Office.

Details released to the JC under Freedom of Information legislation reveal that the Ministry of Defence and the Department for International Development each had five representatives at the Political Islam seminar, held last month at the School of Oriental and African Studies in London.

One delegate from the Cabinet Office also attended the sessions, at which Mr Moussawi had been due to give a lecture on the “current politics and prospects” of Hizbollah.

The full fee was £1,890 for the five-day course, which included lectures on al-Qaeda, Islam in Iraq and Islamist groups in the UK.

Matthew Elliott, chief executive of the TaxPayers’ Alliance, said the “lavish” spending was “frankly disgusting. This man and his organisation are committed to violence and the spreading of hatred. British people do not pay their taxes to provide a platform to that kind of bile.”

The revelation came as Immigration Minister Phil Woolas explained that Mr Moussawi had been denied a visa because his presence would have “increased tension between the Jewish and Muslim communities”.

It is the first time the Home Office has acknowledged that Mr Moussawi’s presence posed a clear risk.

Mr Woolas was writing to Hendon MP Andrew Dismore, who had contacted Home Secretary Jacqui Smith expressing a constituent’s concerns.

CST communications director Mark Gardner commented: “We have seen the ugly impact of Hamas sympathisers in Britain and certainly do not need to repeat the exercise with Hizbollah.”

Other attendees at the conference included a member of the London Deputy Mayor’s office, two from the Crimestoppers charity and five apiece from the Foreign Affairs ministries of Denmark and Finland.

UK government spokesmen said staff needed to “improve their understanding of the current thinking and arguments” on Middle East-related issues and there was “intrinsic value” in their attendance.