INTERNATIONAL efforts to combat terrorism will be given a high profile political boost tomorrow by governments of some of the world's most powerful countries amid warnings from their intelligence agencies that the nature of the threat has changed beyond recognition.

With the bombing at the Atlanta Olympics, the downing apparently by a bomb of TWA flight 800 and a sudden resurgence of terrorism on their minds, foreign and interior ministers from the US, Canada, Britain, France, Germany, Italy, Japan and Russia meet in Paris to map out a plan of action.

Diplomats say the ministers will approve 25 recommendations for international action, including better intelligence sharing, a crackdown on fund raising, and marking explosives and other sensitive materials to facilitate detection.

But with a growing realisation of the increasingly diffuse and transnational nature of terrorism, they will also be calling for closer inter governmental co-ordination in areas that were once considered exclusively domestic.

As the men of violence have changed from the state sponsored organisations of the seventies to amorphous networks, especially of radical Islamic groups, so attention has shifted to closing perceived loopholes in national asylum and immigration laws that allow terrorists to operate across frontiers.

Britain, represented by Mr Malcolm Rifkind and Mr Michael Howard, is advertising practical measures that include amending a UN convention whereby anyone planning or funding terrorism could be refused asylum.

It also intends to extend the law of criminal conspiracy, making it an offence to engage in conspiracy with others, or to incite others, to commit terrorist offences abroad.

Britain has been anxious to play a leading role because it has been widely accused of providing a safe haven for Islamic fundamentalists the Saudi exile Dr Muhammad al Masari is only the most well known example. France, Algeria, Egypt and Tunisia all have similar complaints about London.