The UK has been ranked 10th in the world for its vulnerability to a terrorist attack.
Britain has a high number of symbolic targets
Britain's close relationship with the US, its role in the Iraq war and a "sophisticated militant Islamic network", were key reasons cited by the study.
It also highlights the UK's high number of symbolic targets such as the Houses of Parliament.
In the study, by risk assessment group the World Markets Research Centre, the UK was ahead of Russia, Liberia, Yemen and Lebanon as a country most likely to be targeted.
Colombia, Israel and Pakistan head the Global Terrorism Index for 2003-04, with the USA in fourth place.
Risk assessments for terrorism were carried out in 186 sovereign states and against
countries' overseas interests for the next 12 months.
Terror Top Ten
4. United States
10. Sri Lanka
Countries were given points out of 10 for five risk criteria - the motivation,
capabilities and presence of terrorist groups, the potential scale of the damage
and the effectiveness of counter-terrorism forces.
The Home Office said it had acknowledged the study.
"We are still in a designated public state of emergency
in regard to international terrorism so this index does not
tell us anything we do not already know," said a spokeswoman.
But the government agreed the threat from terrorism "remains real and serious" and vowed to be vigilant.
Guy Dunn, director of research for the WMRC, described Britain as the "most prized target in western Europe".
He said the country was also vulnerable because there is already a "sophisticated militant Islamic network in place".
Mother of parliaments
Mr Dunn admitted the UK had a "strong counter-terrorist capability" but warned that al-Qaeda's signature was to conduct "synchronised and symbolic terrorist attacks".
"London is probably unique in the world for the sheer number of symbolic targets," he said.
"So if the attack on the World Trade Centre is an attack against western
capitalism, or US capitalism, what price an attack against the mother of
But Dr Magnus Ranstorp, Director of the Centre for study of Terrorism and Political violence at St Andrew's University, said the study had limitations and that its findings were only a "rough guide".
"I was surprised by the methodology in that it only gave a 10% weighting to counter-terrorism policies - at present there is international co-operation on an unprecedented scale which influences this country's capability in tackling terrorism.
"An instrument is only as good as how you calibrate it. Unfortunately the international dimension was not taken into account. To rank the UK 10th in the world is a disproportionate measure of the scale of the threat."