The former chancellor Alistair Darling turned down an offer to be a member of a trust to refurbish No 10 and No 11 Downing Street, citing grave concerns about the potential for donors to expect political favours, the Guardian understands. The former chancellor, one of only three living Labour politicians to have lived in Downing Street, is understood to have been approached because of this connection to the building while there was a desire within the Cabinet Office for the trust to be established on a cross-party basis. Boris Johnson’s former chief of staff Dominic Cummings revealed on Friday that he had been deeply opposed to soliciting donations for the flat’s refurbishment – towards which Johnson has now paid £58,000. Reports have alleged that the flat was initially paid for by a donation to Conservative Campaign Headquarters (CCHQ), which lent the money to Johnson. It is understood that the Cabinet Office approached the office of the Labour leader, Keir Starmer, office in July 2020 to speak to Darling. Darling was told the trust was to maintain the buildings in Downing Street and that it would be similar to the arrangements for the White House, where private donors can contribute to upkeep. Darling believed the intent was to maintain state rooms and offices and it is understood civil servants did not raise the refurbishment of the prime minister’s personal quarters. Darling is said to have immediately expressed concern about the plans – first due to a belief that the state has a duty to maintain the iconic buildings, and second because of what he saw as a significant threat of cash for access. It is understood Darling advised that donors might expect political favours, access to the prime minister, peerages, honours or tours of the property. Darling is also understood to have been concerned when he was told the other name involved was Lord Brownlow, a Conservative donor. Darling informed the Cabinet Office the following day that he did not want to be involved, it is understood, and wrote to Starmer to convey his decision and voice his concerns, so the party would be informed in case the Cabinet Office decided to approach other Labour politicians. He is believed to have told Cabinet Office civil servants that the trust plans were unworkable. The head of the civil service, Simon Case, said on Monday that the idea of a trust had been looked into but would not have worked. “A charitable trust can’t cover private areas of Downing Street, so that’s clear that that can’t be done,” he told MPs.