Rishi Sunak has become the most senior government figure to express regret over the Owen Paterson affair, saying the government “must do better” in upholding standards in public life, as Conservative MPs continue to be mired in sleaze allegations. The prime minister took the unusual step on Wednesday of insisting the UK was “not remotely a corrupt country,” after a tumultuous week in which he reversed a decision to prevent the former MP, Paterson, being censured for paid lobbying. Since the botched attempt to protect Paterson, a string of stories has emerged about Tory MPs with lucrative outside interests. But Johnson has not apologised for initially trying to avert a 30-day suspension for the disgraced former MP. Sunak, himself a multimillionaire, was asked about the probity of MPs taking on second jobs in addition to the £82,000 they receive for representing their constituents. “I think people will have different motivations for doing what they do,” he said. “The pay is set by an independent body. That’s absolutely right,” he told Sky News. “And with regard to second jobs, there’s an independent process that we have that is set by parliament that governs all of those things and it’s absolutely right that process is followed to the letter.” He added: “On the broader point and just reflecting over recent events, I think for us as a government, it’s fair to say that we need to do better than we did last week and we know that.” Sunak’s comments came as Lord Evans, the independent chair of the Committee on Standards in Public Life, said MPs should not be spending a “huge amount of time” on a second job. Referring to recommendations his committee made in 2018, he said: “We said that the critical thing was that nothing that an MP does should get in the way of their ability to work in support of their constituents – so the amount of work they do, the sort of work, needs to be judged against that. If somebody is spending a huge amount of their time on a second job, then they can’t be maintaining support for their constituents.” Asked how much time on an external job was appropriate, after revelations that Cox had taken part in a lengthy inquiry on behalf of the British Virgin Islands authorities, Evans asked: “Is it clear that the MP, who has been elected by their constituents, that their main focus, their main priority is on being the best MP that they can be?” Boris Johnson pointedly declined to defend Cox when given the opportunity to do so on Wednesday. Instead he emphasised that all MPs should put their constituents first, and that those who broke the rules must be punished. Cox released a statement on Wednesday in which he said it was up to the standards commissioner, Kathryn Stone, to judge whether he had broken parliamentary rules – and up to his constituents to decide whether he should continue to be their MP. “Sir Geoffrey’s view is that it is up to the electors of Torridge and West Devon whether or not they vote for someone who is a senior and distinguished professional in his field and who still practises that profession,” the statement said. Evans urged the government to implement recent recommendations made by his committee, which was set up by the former Conservative prime minister, John Major, after the cash-for-questions scandal. In a report published last week, before the Paterson affair, the committee called for a series of changes, including better transparency around lobbying and tougher oversight of ministerial behaviour. Decisions about whether a minister has breached the ministerial code lie solely with the prime minister. Alex Allan, the prime minister’s independent adviser on ethics, resigned last year after Johnson chose not to act on a report about the home secretary, Priti Patel. Allan found Patel had displayed “behaviour that can be described as bullying” and that she had “not consistently met the high standards expected of her”.