Court to rule on Bush's ABM plans

Members of the US Congress are taking President George Bush to court in an eleventh-hour attempt to stop him pulling out of the anti-ballistic missile treaty, long considered a crucial check on the global proliferation of long-range and nuclear weapons.

The decision to leave the treaty is due to come into effect tomorrow, clearing the path for the controversial missile defence system enthusiastically supported by Bush administration hawks.

Construction of underground missile silos - the first part of the system - is due to begin in Alaska on Friday.

But yesterday afternoon 30 Democrats in the House of Representatives and one independent congressman announced a lawsuit naming Mr Bush, Colin Powell, the secretary of state, and the defence secretary, Donald Rumsfeld, accusing them of violating the constitution by not consulting Congress before deciding to withdraw.

Republicans say the historic treaty, signed with the Soviet Union in 1972, is an outdated relic of the cold war which does not equip America to deal with threats from terrorist organisations or "rogue states".

"The constitution of the United States is being demolished, and we need to challenge that in court," the Ohio congressman Dennis Kucinich, the lead plaintiff, said at a news conference yesterday.

Lawyers for the politicians said they were seeking a restraining order preventingthe withdrawal, but added that if a ruling was made after tomorrow it could be retroactive, forcing the administration to rejoin the treaty.

One Democratic senator, Russ Feingold of Wisconsin, said he was seeking clearance from his ethics committee to join the lawsuit. "The Senate at a minimum should be consulted on withdrawing from a treaty, and especially from a treaty of this magnitude," he said.

The legal debate hinges on whether treaties qualify as "the law of the land", requiring the approval of congress as does federal law.

Both houses have rejected attempts by Democrats to vote on resolutions demanding that the president consult them on his decision, which was taken six months ago.

There was no comment from the Bush administration on the lawsuit last night.