The former cabinet minister says the Labour leader still has the “2019 manifesto round his neck”.
The former cabinet minister Lord Mandelson, a key architect of New Labour, is urging Sir Keir Starmer to begin a review of the party’s policies.
The Labour peer said Sir Keir needed to start the process as “he still has the 2019 manifesto around his neck”.
The manifesto, written under the leadership of Jeremy Corbyn, advocated nationalisation of key industries.
In the 2019 general election, Labour suffered its worst election result since 1935.
The party won 203 seats, and saw its vote share fall by eight points.
Lord Mandelson said “it would be wrong to make too many specific commitments early in the parliament”, but his party needed polices which were “radical, credible, affordable”.
His comments come as Sir Keir’s first anniversary as Labour leader approaches next month.
When Lord Mandelson was Labour’s director of communications, a previous Labour leader, Neil Kinnock, launched a two-year review in 1987.
It led to the party ditching its support for unilateral disarmament.
Lord Mandelson was instrumental in changing Labour’s image and in moving its policy offer towards the centre ground.
He has been talking to members of Sir Keir Starmer’s team who want to chart a route from opposition to government.
Lord Mandelson said Sir Keir “radiates competence” and praised his stance in some of the internal battles during his first year as Labour leader.
He said he had shown courage by suspending Jeremy Corbyn but that his leadership will be “tested and tested again” and he had to be willing to take “a lot more risk”.
Lord Mandelson argued that the Covid crisis had overshadowed normal politics.
He said: “Covid eclipsed everything else. Without it, Keir would have been able to do more in day-to-day politics. We have lived through abnormal times, and although he has been tested by it, there is clearly a lot more to do.
“He needs to now pick up speed and work out a real argument and point of difference with the government”
He played down expectations for the forthcoming local elections in England adding: “I am not expecting a seismic bounce as people are still focussed on putting Covid behind us.”
But he remained optimistic for the party’s future, describing Sir Keir as “a great asset” and said under his leadership Labour is “now firmly back in the ring”.
Many on Labour’s Left are concerned that the party will try to move away from some of the radical policies which were adopted under Jeremy Corbyn who remains suspended from the Parliamentary Labour Party.
The former MP Laura Smith, who lost her Crewe and Nantwich seat in 2019, told the BBC she blamed Brexit, rather than the party’s last manifesto, for the election defeat.
She argued it would be wrong to move away from policies that were a clear alternative to those offered by the government.