Tony Blair is preparing to make his long awaited announcement setting out his plans to step down as Labour leader and UK prime minister.

Blair will tell Cabinet colleagues first, before outlining his plans in a speech in his Sedgefield constituency.

His spokesman said Blair would be "focused" on being prime minister until Labour has chosen his successor - a process expected to last seven weeks.

Chancellor Gordon Brown is the clear favorite to succeed Blair.

Downing Street' has confirmed the sequence - though not the precise content - of the announcements ending weeks of speculation over exactly when Blair would go public with his retirement plans.

His decision to make his first public statement on the subject in Sedgefield on Thursday follows a longstanding pledge to voters there that they would be the first to know about his future plans.

'Paralysis'

Blair was mocked in the Commons on Wednesday by Conservative leader David Cameron for presiding over a "government of the living dead".

He accused the government of being in "paralysis," with key Blairite ministers either quitting or waiting to be sacked by Mr Brown.

Blair countered that he would be concentrating on "policies for the economy and health, and education and law and order" during the seven weeks he is expected to stay in Downing Street while his Labour successor is chosen.

With a resignation announcement imminent, the Liberal Democrats have tabled a Parliamentary motion urging the Queen to dissolve parliament and call a general election.

Domestic issues

The prime minister's official spokesman stressed Mr Blair still had lots of work to do on domestic issues before he quits.

There were two policy review papers on the role of the state and on families and two white papers on planning and energy security yet to be published, he said.

And there would also be international matters to deal with in the run-up to this summer's G8 and EU summits.

The former Cabinet minister and current European Union Commissioner for Trade, Peter Mandelson, said he would support the next Labour leader and denied that Mr Blair's last weeks in office would be as a lame duck leader.

"'He's going of his own choice. He's doing it at a time which he thinks is good for the country, is good for the government."

Frantic activity

Blair's announcement will trigger three days of frantic activity at Westminster, starting on Monday, as Labour leadership and deputy leadership hopefuls seek nominations from fellow MPs.

Brown has already been nominated by more than half of the Parliamentary party and will almost certainly not face a Cabinet-level challenge for the leadership, after all of the likely runners refused to stand against him.

Left wing backbenchers John McDonnell and Michael Meacher are battling to gain the 44 nominations needed to get on to the ballot paper and ensure there is a contest.

Whoever has the least support will withdraw, giving the other a clear run.

Six deputy leadership hopefuls will also be battling for nominations to enter the race to replace John Prescott, who is due to stand down with Blair.

PHOTO CAPTION

Prime Minister Tony Blair (R) visits British troops in Basra, southern Iraq, in 2006. (AFP)