Boris Johnson “unwisely” embarked on a refurbishment of his official Downing Street flat without knowing how it would be paid for, according to a report that found a “significant failing” by officials. The Tory peer and party donor David Brownlow, and the Conservative party, initially stepped in to settle bills, said the report by the new independent adviser on ministers’ interests, Christopher Geidt. However, Lord Geidt said that given factors such as the ongoing Covid pandemic, and Lord Brownlow’s status as an existing party supporter, he was happy that “no conflict (or reasonably perceived conflict) arises as a result of these interests”. Johnson did not breach the ministerial code, Geidt ruled in an annexe published alongside the much-delayed list of ministers’ interests, and said the interests had now been properly declared by the prime minister. But in criticism of Johnson, he said: “The prime minister – unwisely, in my view – allowed the refurbishment of the apartment at No 11 Downing Street to proceed without more rigorous regard for how this would be funded.” Labour called for any official documents related to Brownlow’s role to be published, saying it was “staggering” that Johnson could set out on the project without knowing how it would be paid for. Angela Rayner, the party’s deputy leader, said: “We know this isn’t the only aspect of the prime minister’s lifestyle that may be being funded by Tory donors – No 10 must now come clean about how far this goes.” The confusion seemingly took place because after Johnson became prime minister in summer 2019, it was agreed that a blind trust should be set up to pay for refurbishment works above the £30,000-a-year amount provided officially. Renovations began last April, while Johnson was in hospital with coronavirus. Under rules at the time, construction work was allowed, although with significant precautions. While Johnson was advised that the trust could cover “some if not all” of the costs, initially the Cabinet Office footed the bill, passing the charge on to the Conservative party. Geidt said there was “no evidence” Johnson was aware of either of these transactions. Legal advice received by the government in mid-June then raised doubts about whether the trust could in fact cover the costs, with Brownlow appointed its chair in July. In October, Brownlow paid the money “directly” to a supplier; no figure was given for the costs, which are reported to have been up to £200,000. In April, the Daily Mail published details of an email from Brownlow in which he said he was making a £58,000 donation “to cover the payments the party has already made on behalf of the soon-to-be-formed ‘Downing Street Trust’”. Geidt said he found Johnson knew nothing about the payments made by Brownlow “until immediately prior” to newspaper reports in February this year. Johnson then “settled the full amount himself” on 8 March. Scathing in his criticism about how work on the trust had proceeded, Geidt said it was “not subjected to a scheme of rigorous project management by officials”, calling this “a significant failing”. “Cabinet Office officials appear not to have acted on this information to the extent of informing the prime minister, let alone offering him advice on his private interests,” he wrote. While Johnson and Brownlow were in contact during the relevant months, there was no evidence that the peer told the prime minister he had paid the bill. Under normal circumstances, Geidt wrote, a prime minister might reasonably be expected to be curious about the arrangements, and especially the financial arrangements that led to the refurbishment of his apartment at Downing Street. But amid the pandemic, Johnson “simply accepted” that the trust would meet the costs, and was “ill-served” by officials who did not tell him this was not the case. While an interest did arise from Brownlow’s payment, given his status as a Tory peer, the paying of the bill did not place him “under any different obligation to the relationship he already has as leader of the party”, the report added. When Johnson did become aware, Geidt said, he “took steps to make the relevant declarations and seek advice” and thus did not breach the ministerial code, the set of rules laying out proper actions for ministers. A Downing Street spokesperson said the report showed Johnson acted in accordance with the ministerial code, adding: “Other than works funded through the annual allowance, the costs of the wider refurbishment of the flat are not being financed by taxpayers and have been settled by the prime minister personally.” Separately, the Electoral Commission said last month it had begun a formal investigation into how the refurbishment work was paid for, saying there were “reasonable grounds” to suspect that multiple offences might have been committed. As a backbench MP, Johnson was free to earn significant sums outside parliament, including £22,000 a month for a weekly column in the Daily Telegraph. One No 10 insider says he regularly complains about not having enough income to maintain his lifestyle. The list of interests is usually published every six months, but had been last updated in December. Part of the delay was because the former adviser on ministers’ interests, Alex Allen, resigned in November after Johnson refused to take action against Priti Patel when an investigation found evidence that the home secretary had bullied civil servants.