The Register of Members' Financial Interests published on Monday evening disclosed several hundred thousand pounds of donations and in-kind support given to Andy Burnham in the weeks before he entered Downing Street, in the first entry the Prime Minister has filed as an MP since returning to the Commons.

The BBC put the total at £345,000. The Press Association reported donations worth more than £325,000 in the three months before he took office, covering May to July, while the Guardian reported "almost £350,000" across the months before he became Labour leader. The variation appears to reflect different date windows applied to the same register entries.

The largest single backer is Lord Sainsbury of Turville, the former Labour science minister and long-standing party donor, who provided office space and the cost of contractors working on "policy and operations" from June, valued at £164,347, according to PA. Other declarations include:

Lord Blunkett also donated towards the Makerfield by-election campaign, recorded by PA as £2,000 and by the Guardian as £10,000. Four trade union donations of £5,000 each — from the Fire Brigades Union, its north-west regional office, the Communication Workers Union and Unison — were made between March and April for mayoral campaigning, at a point when speculation about Mr Burnham's return to Westminster was intense but he had not declared his intentions.

The register also lists hospitality accepted in his former role as Mayor of Greater Manchester, including two tickets worth £3,800 to the Brit Awards from Sony Music and tickets to Glastonbury, where he was speaking. The Guardian valued the hospitality and travel entries at more than £12,000 in total, including £1,500 of Glastonbury tickets in 2025 and £500 of tickets to Ladies Day at Aintree this year. Mr Burnham has additionally declared a London property he owns with his wife, which is rented out, and a newly incorporated company, Office of Andy Burnham Ltd, of the kind party leaders commonly establish to manage their affairs.

A Labour Party spokesperson said:

"It's right that political campaigns are funded by the generous support of party donors, rather than via the public purse. All declarations have been made in line with Parliamentary and Electoral Commission rules."

The disclosures come ten weeks after Mr Burnham publicly backed a cap on political donations to curb what he described as undue influence by big-money donors, a position he first set out during his unsuccessful 2010 leadership bid, when he complained that the contest was too heavily influenced by wealthy backers.

The sums are broadly comparable with recent leadership campaigns. Liz Truss raised more than £400,000 in 2022, though Mr Burnham's contest was effectively uncontested, with 379 nominations and no rival on the ballot.

Mr Burnham won the Makerfield by-election on 18 June with a majority of more than 9,000, and became Prime Minister on 20 July following Sir Keir Starmer's resignation. Sir Keir faced criticism early in his premiership over more than £100,000 in accepted hospitality.

The register also shows Louise Haigh, Chancellor of the Duchy of Lancaster, accepted £11,000 from Lord Sainsbury for legal advice and £7,500 of legal services from the firm Bindmans. A source close to Ms Haigh said the donations related to legal services "in relation to misrepresentation in the media".

No opposition party had responded at the time of writing.