Foreign Secretary Sir Geoffrey Howe said in a statement there was "conclusive evidence" of Syrian official involvement with Mr Hindawi.

It is understood the bomb Mr Hindawi planned to use was constructed at the Syrian Embassy in London and that Mr Hindawi held a Syrian passport normally reserved for government officials.

The Syrian ambassador, Dr Loutof Haydar, said the decision to expel him was "nonsense".

The decision came just hours after Mr Hindawi was sentenced to 45 years in jail for plotting to blow up the Israeli airliner flight to Tel Aviv.

Mr Hindawi attempted to blow up the flight by planting a timer bomb inside his girlfriend's hand luggage. Ann Murphy had been under the impression that he would follow her on a later flight.

The explosives were only discovered when a security official searched the bag thinking it was too heavy. The 3lb of plastic explosives and a detonator concealed in a pocket calculator had made it through two X-ray machines undetected.