A former Conservative cabinet minister who vets ministers and mandarins’ new jobs has called for urgent reform over “anomalies” that allowed conflicts of interest in Westminster and Whitehall. Lord Pickles, the chair of the Advisory Committee on Business Appointments (Acoba), told a committee of MPs he was “very worried” after Bill Crothers, a senior civil servant, was allowed to work part-time, then full-time, for the collapsed finance house Greensill Capital without being vetted. “It also highlights a number of anomalies within the system that require, I think, immediate address,” he said. Pickles was speaking days after his committee released an exchange of letters with Crothers that exposed the Cabinet Office’s unusual arrangement. It allowed Crothers to work for Greensill, which has now collapsed leaving thousands of jobs in the balance, while in charge of billions of pounds of taxpayers’ expenditure. At a meeting of the public administration and constitutional affairs committee (Pacac), Pickles called for a “full and frank” explanation from the government as to how Crothers was able to work part-time for Greensill while remaining in his job as the government’s chief procurement officer. The Guardian disclosed this week that Crothers was allowed to do so by John Manzoni, the Cabinet Office’s most senior civil servant at the time. “I mean, if Mr Crothers had decided he wanted to have a milk round or something, I don’t think we would be terribly worried,” Pickles said. “But his particular position, in terms of running procurement and working for a commercial organisation, is something that does require a full and frank and transparent explanation.” Pickles said he hoped that there was a record of the decision to allow Crothers to join Greensill. “I would have expected that kind of decision to have gone through a process at which at least the Nolan principles would have been applied.” “I sincerely hope it will turn out that there is a record of this and it wasn’t just on the say-so of an individual,” he said. Pickles said he had been warning Cabinet Office ministers and officials of a scandal around second jobs for some time, but not at the level of secretaries of state or the prime minister. “If I had found the machine wasn’t responsive, then I would have wandered down and spoken to a secretary of state or the prime minister,” he said. Pickles said he had pointed out that many of those working in Whitehall, including Lex Greensill who worked as an adviser to David Cameron’s government in 2012, did not have to declare their outside interests or whether they had lobbied officials or ministers for work. “Contractors, consultants, people who arrive and offer assistance, maybe during the pandemic or maybe as Mr Greensill did, they are not covered at all [by the rules],” he said. Crothers, a former head of government procurement, began working for Greensill as a part-time adviser to the board in September 2015 – in a move approved by the Cabinet Office – and did not leave his role as government chief commercial officer until November that year. During the hearing with Pickles, the Pacac chair, William Wragg, announced a “full inquiry into the topical matters around Greensill”, which was approved to administer government Covid support loans before it went bust. MPs on the Commons treasury committee had already announced their own inquiry into the firm’s collapse. It threatens thousands of UK jobs at Liberty Steel, which relied on the group’s financial backing.