The solicitor appointed by Boris Johnson to run an independent inquiry into the Greensill lobbying scandal is a former Conservative party member who stood as a council candidate, the Guardian can reveal. Nigel Boardman, whose appointment prompted concerns that he may be perceived as being too close to the Tories and the government, tried to become a councillor for the party in Islington, London, in 1986. The disclosure, after weeks of government denials that Boardman is too close to the Tories to conduct an inquiry into conflicts of interest, has prompted calls for the inquiry to be abandoned. Johnson appointed Boardman, 70, in April to run an independent investigation into government contracts and lobbying involving a number of senior Conservative politicians including the former prime minister David Cameron, the chancellor, Rishi Sunak, the MP and former health secretary Matt Hancock and the peer Francis Maude. It appeared that the supply chain financier Lex Greensill had been given privileged access to Downing Street when Cameron was prime minister and Jeremy Heywood was cabinet secretary. After leaving government, Cameron became an adviser to Greensill Capital and lobbied ministers including Sunak for access to government-backed loans. Boardman’s appointment was criticised because he is a paid non-executive director to the Department for Business, Energy and Industrial Strategy (BEIS), and is a long-term adviser to the law firm Slaughter and May, which was awarded £7m in government contracts over the last year. He is on the board of Arbuthnot bank, which has close ties to the Conservative party. His father, Lord Boardman, was a former government minister and Tory party treasurer under Margaret Thatcher. Asked in April if Boardman was a friend of the Conservatives, the prime minister’s spokesperson praised Boardman’s independence. “He was asked to lead this review independently and he’s been asked to do it thoroughly and promptly. We trust him to do that.” Documents from the May 1986 London borough elections show Boardman had even closer links to the party. He stood as a Tory councillor in Junction ward in north Islington, north London, where he lived at the time. He came ninth out of 10 candidates after receiving 491 votes, losing out to Labour, the SDP-Liberal Alliance and his Tory colleagues. He was an “active member” of the local party, a former associate said. A number of senior figures have previously questioned whether Boardman is the right person to run an inquiry into conflicts of interest. Suzanne Heywood, whose husband, Jeremy, was the cabinet secretary when Greensill entered Downing Street, questioned his suitability in an interview with the Guardian. Asked to comment on Boardman’s previous Conservative party membership and whether he had declared it before taking up the role on the inquiry, sources said he had not been a member of a political party for more than 20 years. A Cabinet Office spokesperson said: “This is an independent review. Nigel Boardman is a distinguished legal expert, having undertaken a number of reviews scrutinising the government, and he was asked to lead this review following the appropriate due diligence checks. “The review is ongoing, and as we have set out, we will publish and present his findings to parliament and the government’s response, in due course.” Labour’s deputy leader and shadow chancellor of the duchy of Lancaster, Angela Rayner, said Boardman’s former Tory membership was further proof that the inquiry should be dropped. “After stuffing non-executive director posts with political acolytes, it appears the prime minister is now appointing Tory cronies to lead investigations too,” she said. “This investigation is clearly independent in name only and needs to be scrapped in favour of a properly independent investigation that will get to the bottom of what has been going on at the heart of government.”