Conservative leadership candidates have declared more than £140,000 in donations for their campaigns, but the frontrunners have so far kept quiet about their backers.

Updates to the MPs’ Register of Interests published on Thursday showed Liz Truss had not yet declared any donations to her campaign, while Rishi Sunak had revealed only the loan of some office space in Westminster worth £3,195.

The office space was donated to the former chancellor by Bridge Consulting Ltd, co-owned by former Conservative Party and O2 marketing boss Will Harris.

The records also show Suella Braverman’s unsuccessful campaign received £10,000 from First Corporate Consultants Ltd, a company owned by leading climate sceptic Terence Mordaunt.

Mr Mordaunt, not thought to be related to former leadership candidate Penny Mordaunt, also owns Bristol Port and chaired the Global Warming Policy Foundation (GWPF) between 2019 and 2021.

Conservative leadership bid
Attorney General Suella Braverman’s campaign received £10,000 from a company owned by climate sceptic Terence Mordaunt (Stefan Rousseau/PA)

The GWPF has lobbied against climate change policies such as net zero and was sanctioned by the Charity Commission in 2014 for breaching rules on “balance and neutrality”.

Mr Mordaunt remains on the GWPF’s board of trustees, along with former Conservative chancellor Lord Lawson and MP Steve Baker, a key figure behind the climate-sceptic Net Zero Scrutiny Group.

Tom Tugendhat declared the largest amount of donations of any leadership candidate, listing more than £120,000 in his register of interests.

Some £42,673 came from Policy Focus Ltd, a London-based company set up only 10 days before Boris Johnson’s resignation and owned by property developers Christian Sweeting and Robert Luck.

Conservative leadership bid
Tom Tugendhat has declared more than £120,000 in donations to his unsuccessful campaign (Henry Nicholls/PA)

Mr Tugendhat also received £50,000 from long-standing Tory donor Ian Mukherjee and £25,000 from Beacon Rock Ltd, a company owned by former Conservative Party treasurer Sir Michael Davis.

He received a further £6,000 from business consultancy InvestUK Group, which has previously supported Mr Tugendhat’s work as chair of the Foreign Affairs Committee.

Kemi Badenoch raised £12,500 to support her bid for the Tory leadership, including £10,000 from Longrow Capital, owned by tech-focused investor Dave Maclean.

She also received £2,500 from Joanne Black, for whom no further details are available.

Penny Mordaunt, Sajid Javid, Jeremy Hunt and Nadhim Zahawi are yet to declare any financial support for their campaigns.

MPs have 28 days from accepting a donation to declare it to parliamentary standards authorities, with the latest publication covering the period up to August 8.