Labour's favourite think-tank has said that Gordon Brown's bid to articulate his political vision "has not come across very well".
In an interview with the Parliamentary Monitor, the new directors of the Institute for Public Policy Research said the prime minister must use the Queen's Speech to establish the government's direction.
Carey Oppenheim and Lisa Harker advised Brown when he was chancellor and now say it is vital that he clarifies his aims after losing ground to the Tories.
In a separate article in the Monitor, another Labour adviser, Lord Giddens, says that the Queen's Speech is a vital part of the "fightback".
Former Number 10 insider Oppenheim said: "It is clear that Brown has a vision, the problem has been that it has not come across very well.
"Now that we are moving away from the period of political froth about the election, there is an opportunity to hear more about what that vision is."
IPPR co-director Harker added: "There is no doubt that Gordon Brown is a man of great intellect and political vision and it would be extraordinary if he didn't use that opportunity to set out his vision for Britain.
"We have had some components of that. In his conference speech he said it would not be as simple as equality of outcome or opportunity: his vision is a combination of those things.
"He has talked about a society of common bonds and mutual obligations and civic duties. So we have got some of the elements of the vision, but we need to see how the vision underpins policies, and the integration between the philosophy and the policies, and that is yet to come. He must use the Queen's Speech to do that."
In his article, Lord Giddens said: "Against the background of Labour's current troubles, this year's [Queen's] Speech has a special significance."
"It has to be part of the fightback to re-establish the prime minister's authority and to show the public that this is a government with a clear view of where it wants to take the country," the peer wrote.
"Mr Brown broke with tradition and decided to give an early preview of the speech several months back as part of his drive to make the business of government more open and accountable. The idea was to give Parliament and citizens a chance to comment before the government's programme was finalised.
"The citizens' consultations have taken place, but so far as I know, there is no indication of what impact they have made. It is important to show at some point that they have made a difference, or otherwise, why hold them?"
