Brown admits that he is in dark over when Blair will stand down

Gordon Brown says that he does not known when Tony Blair plans to quit as Prime Minister.

In comments that will reignite speculation about the handover of power between the two men, the Chancellor confirmed that he had not been told when Mr Blair intended to relinquish power.

But speaking at the end of a trip to Mozambique, Mr Brown issued a coded message to "outriders", such as the arch Blairite former cabinet minister Alan Milburn, to stop party infighting, insisting he would focus "all my fire" on the fight against David Cam-eron's Conservatives in the run up to the May local elections.

Mr Brown also hinted that he was planning to remain in power for the long term when he eventually did get the keys to No 10, saying he was planning to tackle challenges facing Britain over the next 10 to 15 years.

Mr Blair is understood to have decided a timetable for stepping down, after he pledged not to fight the next general election, but has refused to announce a departure date.

Asked whether he knew the date in Mr Blair's mind, Mr Brown replied: "That is not for me either to speculate about or to think I know something about dates. It's for him, when he decides, to make his announcement."

He said: "What I know is what I've told you, that Tony Blair has said he is not standing at the next election as leader of the Labour Party. He has said to the Parliamentary Labour Party that he wants to play his part in organising a stable and orderly transition. The rest is up to other people."

Mr Brown's comments come after a week of speculation about relations between him and Mr Blair. The pair did not take questions at Labour's local election campaign launch amid reports of friction, while the party's former deputy leader Lord Hattersley said at the weekend that feuds between rival camps loyal to the two men were "ruining the party".

Mr Milburn launched an attack on Mr Brown's tax plans in the Budget debate and refused at the weekend to rule himself out of standing for the Labour leadership when Mr Blair stood down. Mr Brown refused directly to criticise Mr Milburn, saying he had praised the Budget.

However, he emphasised that he would devote all his energies to demonstrating that the Conservatives had failed to meet the big challenges facing Britain despite Mr Cameron's leadership.

Mr Brown outlined a series of major long-term policy initiatives he would be launching in the coming weeks. He will host talks at Downing Street in 10 days on the economic, social and political consequences of global economic change before travelling to America to make a speech on future reform of the World Bank and the International Monetary Fund.

He is also planning a speech on the environment and climate change, one of a series of long-term policy pronouncements which go far beyond his Treasury brief and that have fuelled speculation that the handover of power has already begun.