John Prescott has defended Ed Miliband's right to dismiss the work of the IPPR think-tank, declaring in a Sunday newspaper: "These wonks can be pretty precious."
The former deputy prime minister hit out at IPPR and its supporters after Miliband chose to highlight just one policy from its recent Condition of Britain report.
Prescott, writing for the Sunday Mirror, suggested the recent criticisms of Miliband's leadership were the result of disquiet with his limited enthusiasm for their proposals.
He singled out left-leaning backbencher Jon Cruddas, who is leading Labour's policy review, for criticism. Cruddas was taped at a meeting complaining a "dead hand" was blocking "bold policies".
"Cruddas told one meeting Labour needs to treat people as 'context transcending spirits'," Prescott wrote.
"No, Jon – we should start treating them as normal people and talk to them in a language they bloody well understand. Parties mustn't be led by wonks, lecturers and think-tanks."
Labour's policy forum meets in just two weeks to discuss what will be in the party's 2015 manifesto.
"In the 1970s we used to take ideas for policies to the party conference and vote on which ones we liked. They could come from party members, trade unionists and experts," Prescott wrote.
"These days the work of coming up with policies has been outsourced to think-tanks – often made up of members of rival parties."
He likened the status quo to a school pupil preparing to take an exam and getting "someone else to do it for you".
"Labour's policy forum must put the party members' stamp on the manifesto," Prescott argued.
"If they want to be credible they should listen to the people and craft policies for them. Labour won three elections with that approach. So let's do it again."