Labour chairman Hazel Blears rejected calls for a timetable for Tony Blair going despite two poor by-elections.
Mr Blair's departure has been under the spotlight
In Blaenau Gwent, Labour came second to independent Dai Davies. In Bromley and Chislehurst it came fourth behind UKIP.
The result reignited the debate about when Mr Blair will hand over power, probably to Chancellor Gordon Brown.
One press report predicted Mr Blair would warn Labour will lose power if it stops renewing itself when he makes a speech to Labour's policy forum.
The Independent quoted a "close ally" of Mr Blair as saying: "He is leaving, but New Labour must not leave with him. He wants more New Labour not less."
Ms Blears acknowledged there were issues over Mr Blair's leadership but said critics would not get "this fabled, mythical timetable".
"Clearly there are issues around because the prime minister has said that he is not going to stand at the election. Clearly, that is going to be around the place," she told the BBC.
Meanwhile Education Secretary Alan Johnson has warned Labour against lurching to the left.
He acknowledged progress made by the Tories under David Cameron and argued any shift to the left would play into the Conservative leader's hands.
"Cameron is paying us the tribute of imitation - he has realised that he can only win by occupying the centre ground and he's banking on a hunch that if he occupies that ground we'll leave it for the electoral fringe that we consigned ourselves to 25 years ago," he said.
"Yes we need new ideas, fresh initiatives and renewal in government but it has to build on where we are now - a party proud of its record in government, firmly based on the centre-left and able to appeal in all constituencies across the United Kingdom.
"We vacate that territory at our peril."
Mr Johnson, who recently said he would like to be deputy Labour leader if a vacancy arose, said reform was necessary because without it Britain would fall behind - it was not a "test of our political machismo".
Ex-minister Michael Meacher recently suggested Labour might lose the next election if it failed to shift direction.
Dai Davies and Trish Law triumphed over Labour
Wales First Minister Rhodri Morgan said the party must start listening to people. He said it was sometimes "therapeutic" to get a "political kicking".
Mr Morgan said it was important Mr Blair went out on a high and was not forced out - though he would not say when the prime minister should go.
Elections to the Welsh Assembly are due to take place next year and Labour MP Paul Flynn said Mr Blair should go six months ahead of those.
Meanwhile in the Westminster by-elections independent Dai Davies won the Blaenau Gwent seat in south Wales, which Labour lost in 2005 to the late Peter Law when he overturned its 19,000 majority.
Meanwhile Tory Bob Neill held Bromley and Chislehurst, in south-east England, but their 2005 majority was slashed from 13,342 votes to 633 by the Lib Dems.
Labour's National Policy Forum oversees the development of policy within the party. All those who sit on the party's ruling National Executive Committee are members including Tony Blair.