Tessa Jowell is unfazed about being banished into the political wilderness. Her staunch support for Tony Blair and New Labour risks leaving her out of step with her party. "The era of New Labour has passed," said Ed Miliband upon winning the contest for the Labour leadership. "Today a new generation has taken charge of Labour."

Jowell says she isn't worried. "Am I bothered?" she shrugs, doing a good impression of Lauren Cooper, the stroppy teenager created by Catherine Tate.

An hour later, the woman who conceived Sure Start and guided the London Olympics for eight years is fighting back tears as she describes the most difficult episode from her time in government. Bothered? The question may be rhetorical, but you can't help but conclude that, yes, Tessa Jowell most definitely is.

Back in September last year, Ed Miliband declared that Labour needed a new narrative. ‘New Labour is dead! Long live the New Generation!' Or something like that.

But a succinct, vote-winning message is proving difficult to find. New Labour is old, Old Labour is ancient and Next Labour? Well, that was David Miliband's idea, and we know what's happened to him.

Only two Labour soundbites have gained traction since last September: the "new generation" and the "squeezed middle". The former was mentioned 14 times in Ed Miliband's hour-long conference speech; the latter encompasses 90 per cent of the population, according to a Miliband radio interview.

So much discussion of what Labour is not has occupied political commentators that defining what it actually is, post-New Labour, leaves only disjointed fragments.

Tessa Jowell has been described as New Labour's "most senior cheerleader". She is completely unapologetic about it. "Why should I apologise?" she retorts. "For supporting a set of ideas, and values, and a way of doing politics, that represents the popular consensus? I am proud of being New Labour. I am proud of being a Blairite. I am proud of being part of three governments."

Her attachment to New Labour is founded in sentiment, more mummy than militant New Labour. She is godmother to one of Alastair Campbell's children; Peter Mandelson is godfather to her son. Back in the early 1990s, those chewing the Labour fat around her dinner table included Cherie and Tony Blair, Harriet Harman, Margaret Hodge and David Blunkett. The champagne was served socialist.

Jowell accepts that New Labour will evolve.

"I think Ed has a very particular job to do, which is to harness the credo of power, wealth and opportunity in the hands of the many, not the few, that underpin New Labour - and to translate this into the aspirations, challenges and fears of 2015."

But there is an underlying scepticism about the current approach. She was recently quoted as describing Ed Miliband's reference to the ‘squeezed middle' as "cumbersome and inexplicit". "I am very fixed on how poor we are at communicating a lot of the time," she explains, propped up on pillowed armchairs in her office. "You know how twins have a language they often use with each other that they understand, but nobody else does? Politics is a bit like that. In a way, the squeezed middle is part of that problem. It is a sort of old politics, an attempt to describe a new phenomenon."

Ed Miliband's "blank sheet of paper" was another attempt to pin down a new politics - representing a fresh start on policy. But Jowell recognises there is an issue about how Labour acts an effective opposition in the short term. "It certainly seems that there's a slight reluctance on some issues - without having had this deep-cleanse idea - about what everyone stands for on certain issues. There's a slight reluctance to act in that very natural position in opposition. It's sometimes very difficult to convey these ideas in a way that sounds fresh and new, and is sufficiently nuanced."

"Being in opposition is tougher," she admits. "We lost the election and inevitably there is a period of grace when the country basically wants to say, ‘Labour, we've had enough of you. We're now focusing our attention on the new government.'" Her sentiment echoes that of Ed Miliband, who described being in opposition as "frankly crap".

Tags: Issue 32, Labour, Tessa Jowell