UK poised for major terrorism test

Britain is set for an unprecedented security test as it heads into the formal general election campaign.

Ministers and security chiefs are braced for the threat of a major terrorist atrocity as election day nears.

Despite the close alliance between America and the UK, culminating in the coalition in the Iraq war, Britain has yet to see a terror attack linked to Islamic extremism.

But security chiefs have warned that attacks have been frustrated and predict fresh attempts over coming weeks and months.

Meanwhile, the UK on Monday began a five-day international counter-terrorism exercise with the United States and Canada.

The exercise, referred to as 'Atlantic Blue' in the UK, is part of the Home Office's national exercise programme and has been designed to test simultaneous responses to internationally linked terrorist incidents. 

Ministers have fought hard over recent weeks to persuade MPs and peers to back new laws to put terrorist suspects under house arrest.

The government hopes that these new laws, in addition to a comprehensive security operation underway since September 11, will be enough to prevent al Qaeda mounting an attack between now and polling day.

However the government is mindful of the Spanish general election, during which terrorists linked to the group staged a series of bomb attacks on rush hour trains in Madrid.

The recent breakdown in the Northern Ireland peace process has also heightened fears that the IRA could return to terrorism following several years in ceasefire.