Nancy Pelosi, incoming speaker of the House, suffered an early defeat on Thursday when Democrats rejected her candidate for the number two job in the party leadership.

The unexpectedly bruising battle just days after Democrats took control of the House raised questions about party unity and Mrs Pelosi’s commitment to ethics re-form and dampened celebrations of their new majority.

After a three-hour closed-door meeting, Democrats voted 149-to-86 to name Steny Hoyer, a long-time rival of Mrs Pelosi, to be majority leader when the new Congress convenes in January. He defeated John Murtha, the outspoken critic of the war in Iraq, whom she had backed in the race.

Throughout the mid-term election campaign, Mrs Pelosi pledged that the first act of a Democratic-controlled Congress would be a tough package of rules and ethics reform, following a series of mostly Republican scandals. But she raised eyebrows this week with her endorsement of Mr Murtha, who has been called “ethically challenged” by government watchdogs.

Mr Murtha has faced allegations that he abused his position as a member of the defence appropriations sub-committee by favouring a lobbying company of a former long-term staffer and clients of Robert “Kit” Murtha, his brother.

He has also been criticised for taking advantage of earmarking, the practice of appropriating funds for specific government projects that benefit individual lawmakers’ constituents. Mr Murtha was also named as a co-conspirator in the 1980 Abscam bribery probe but not indicted in the case.

But Mr Murtha and Mrs Pelosi have long been allies in the Capitol and veteran lawmakers said her support for him was a sign of her loyalty. Others saw a vote for him as a way to thank him for his leadership on the war, a stance that played a large part in their victory.

The result will force Mrs Pelosi and Mr Hoyer, her current deputy, to continue to work together. Both natives of Maryland, they have known each other for 40 years and have sparred frequently.

Republicans in the House are set to choose their new leadership team today. Dennis Hastert, the outgoing speaker, will not be a candidate for a top party post.

John Boehner, who became Republican majority leader after Tom DeLay resigned his leadership job amid allegations of campaign finance violations, is the front- running candidate to be minority leader.