THE US Supreme Court today reversed a state court decision for recounts in Florida's contested election - all but transforming Republican George W. Bush into the president-elect.

Some senior Democrats urged Vice President Al Gore to give up his challenge after five weeks of the US election.

Gore "should act now and concede," Ed Rendell, the chairman of the Democratic Party said less than an hour after the court issued its late night ruling five tumultuous weeks after the US voted.

Gore's lawyer W. Dexter Douglass said: "It sounds like we lost."

"What else can we do?" he said. "It means we can't do the recount."

Still, another legal adviser said the justices' order sending the case back to the Florida Supreme Court might offer at least some hope that recounts could be conducted under a new standard.

Gore was reviewing the decision with his staff and attorneys, and had not decided how to react to it, several sources said.

Bush's attorneys also were reading the decision closely to determine whether it gave Gore any hope of a recount.

"It's clear the decision has been reversed," said spokeswoman Mindy Tucker. "It's clear that the recounts that they've ordered will not happen. Beyond that, our attorneys are still looking at the decision and we'll have further comment later."

In an extraordinary late-night decision, the justices said the recount ordered last weekend by the Florida Supreme Court could not be completed by the deadline.

Without the state's 25 electoral votes, neither Bush nor Gore had the 270 votes in the Electoral College needed to become president. With them, victory was a certainty.

The court's unsigned opinion said seven justices agreed that there were constitutional problems with the recount ordered by the Florida Supreme Court last Friday.

By a 5-4 majority, the justices said the recount ordered by the Florida Supreme Court was unconstitutional because varying methods and a loose standard would be used to count the votes. Further, the justices said no time remained for a new recount.