Prime Minister Tony Blair has denied he is running out of steam as he faces his final months in office, insisting: "I want to finish what I have started".
Mr Blair says he is 'getting on with the job'
In an interview with BBC One's The Politics Show he said he still had a "strong and energetic agenda" of public service reform to carry out.
He refused to be drawn on the timing of his retirement later this year.
But he confirmed he intended to lead Labour into the Scottish Parliament and Welsh Assembly elections in May.
Asked why he had not publicly endorsed Chancellor Gordon Brown as his successor, Mr Blair said: "What I am not going to do is talk about my successor until the moment of my departure".
He also denied his authority was waning, amid recent signs of rebellion such as Northern Ireland Secretary Peter Hain's criticisms of his foreign policy and protests by other ministers against hospital cuts.
Mr Hain's comments were a reflection of the fact he was a contender for Labour's deputy leadership, Mr Blair appeared to suggest, while ministers were entitled to protest against cuts affecting their constituency, he said.
The prime minister repeatedly declined to answer questions on the police investigation into cash for peerages allegations, which has seen two members of his inner circle interviewed under caution.
"Let the thing run its course and then we will see," he told interviewer John Sopel.
Mr Blair also defended the running of the Home Office and the government's record on prisons.
He conceded prisons were "full to bursting point" but he said 20,000 new prison places had been created and there would be a further 8,000 added to that total soon.
He said prison overcrowding was partly due to people being in jail for longer.
He acknowledged the government was experiencing "mid-term" difficulties but said the "fundamentals", such as the economy, were sound.
"I'm getting on with the job, and I want to finish what I've started, if I can put it like that," Mr Blair told The Politics Show.
"And at the present time there are things I am right in the middle of doing, whether it's health service reform, the city academy programme, or the changes we're making in the Home Office or this issue to do with energy policy, or the international issues we've just been discussing - I'm getting on with the job."
Mr Blair pointed in particular to the Northern Ireland peace process as an area on which he hoped to make progress before he leaves office.
"The next few weeks will be as important as the negotiation of the original Good Friday Agreement," he said.
"We will determine whether we have a basis for the future in Northern Ireland, that allows us both to have power sharing between unionists and republicans and nationalists, really on a solid basis for the first time ever."