The U.S. ambassador to the United Nations could become the second senior Bush administration official to lose his job in the wake of mid-term elections this week in which the Democrats won control of both Houses of Congress.

John Bolton was appointed as U.S. ambassador to the UN in August 2005, while Congress was in recess, but that nomination needs Senate approval. The Democrats and a key Republican say they have no intention of confirming his nomination. His temporary appointmentis expected toexpire at the end of this year.

U.S. President George W. Bush announced the resignation ofDefence Secretary Donald Rumsfeld on Wednesday, the day after the mid-term elections. Bolton, who lacks support in the current Senate and is not likely to have support in the next Senate, could be the next to go.

Nomination resubmitted

On Thursday, the White House submitted his nomination again to the Senate in the hope that it passes before the end of the year.Congress begins a new termin January, when the Democrats will be firmly in charge.

The uncertainty over Bolton's nomination comes as the Bush administration is drawing on the UN for support in dealing with North Korea and Iran over their nuclear programs.

U.S. State Department spokesman Sean McCormack said Bolton has made a difference in his position.

"He has been extraordinarily effective up there at the UN and now is not the time to have a gap in your UN ambassador," McCormack told the Associated Press.

Sen. Lincoln Chafee, a Republican who represents Rhode Island, said he will continue to oppose Bolton's nomination. Chafee lost to Democrat Sheldon Whitehouse on Tuesday, but his continued opposition while a member of the Senate foreign relations committee means that the Republicans will not have the votes they need to push his nomination from the committee to the full Senate.

'The people have spoken'

"The American people have spoken out against the president's agenda on a number of fronts, and presumably one of those is on foreign policy," Chafee said. "And at this late stage in my term, I'm not going to endorse something the American people have spoken out against."

The Senate is expected to reconvene next week, but Democrats have said even if the Senate begins to debate his nomination, they couldstretchit outto try to have the nomination quashed. The Republicans, still in charge of the Senate until next year, do not have the 60 votes they need to prompt a vote on the nomination.

Sen. Joe Biden of Delaware, a Democrat on the Senate foreign relations committee, said the nomination is likely to go nowhere.

"I see no point in considering Mr. Bolton's nomination again in the foreign relations committee because, regardless of what happens there, he is unlikely to be considered by the full Senate," Biden said.

With files from the Associated Press