Andy Burnham has been planning to be Prime Minister for a year, says ally

Andy Burnham has been planning what he would do as prime minister for at least a year, a key ally has said.

Louise Haigh, who briefly served as transport secretary in Sir Keir Starmer's government, has been central to the new MP for Makerfield's operation in recent weeks.

"He has been thinking about this and certainly planning for this, for this moment, for at least the last year," she told the BBC's Political Thinking with Nick Robinson.

She added that his route to No 10 only became clear after Labour's disastrous set of election results in May, saying it was obvious "it couldn't continue the way it was continuing."

Burnham is so far the sole candidate to have announced their intention to stand to replace Sir Keir as Labour leader.

Nominations from Labour MPs have now opened and should the former Greater Manchester mayor become PM later this month, Haigh is likely to play a central role in his government.

The MP for Sheffield Heeley is a leading figure on the "soft left" of the Labour Party and has been involved, with Burnham and a handful of other senior figures, in access talks with the civil service, aimed at ensuring a smooth transition of power.

She told the BBC the former Greater Manchester mayor has been thinking about what he would do as prime minister for years, noting that he had twice before run to become Labour leader in 2010 and 2015.

And she denied that he was "unprepared or inexperienced" because of his nine years away from Westminster while Greater Manchester mayor.

"He has spent that time thinking very deeply about how the country is run, what holds regions like Greater Manchester, and therefore most regions and the devolved nations of this country, back.

"He has got very, very clear ideas and a plan to put that right."

She also defended the lack of detail on who might be in Burnham's cabinet, saying he was not "beholden" to anyone - with no need for horse-trading or deals.

"He can set out the agenda... and then build out the people from that. That's the right way to do it, but it's so so rare that you get given the opportunity to do it that way."

One of the big headaches facing a prospective Burnham government is the welfare budget.

A major review of Personal Independence Payments (Pip) in England and Wales published on Thursday found the disability benefit to be "not fit for purpose" and in need of fundamental change.

Opposition parties, most notably the Conservatives, have called for the welfare budget to be cut in order to fund defence spending.

Sir Keir attempted to push through welfare reforms to cut £5bn a year from budget, but was forced into a major U-turn following a backbench revolt, which was led by Haigh among others.

She told the BBC the welfare bill was "ballooning massively", but said the cuts the Labour government had tried to push through would not sustainably bring down the welfare bill because it would push costs up "elsewhere in the system".

Among Burnham's flagship policies is devolving power away from Westminster to regional authorities - and he has indicated he could transfer decision-making away from the Treasury.

"The Treasury is all-powerful and does exert, I think, too much power over other areas of public policy," Haigh said.

But she added: "I think whilst Andy has a clear plan for some of that because he thinks really deeply about rewiring the state, I don't think in two and a half years we've got time to break up the treasury because it would just drag everything down and be a huge distraction."

Haigh's resignation in November 2024 was the first from Sir Keir Starmer's government and came after it emerged she pleaded guilty to a fraud offence a decade prior.

She admitted telling police in 2013 she had lost her work mobile phone in a mugging, but later found it had not been taken.

She was given a conditional discharge by magistrates, following the incident which happened before she became an MP.

Haigh told Nick Robinson she had disclosed her conviction to Sir Keir when Labour was in opposition.

She said the PM had had initially been supportive of her when the story broke in the Times, before his then chief of staff Morgan McSweeney asked for her resignation.

Asked whether Sir Keir's message in summer 2024 after coming to power was too gloomy, Haigh said: "We were elected on a mandate for change, and everyone was hopeful when we came in.

"There was excitement and ambition for a changed country, and the government immediately turned around and said that wasn't possible.

"We've just never been able to recover from that, no matter how many resets [Sir] Keir Starmer and the rest of the government attempted, it could never get itself out of that."