Any attempt by Boris Johnson to “unfairly” install a close ally as head of the National Crime Agency before he leaves No 10 will be thwarted, civil service sources have said. Reports suggest the prime minister is keen to insert his “friend” Lord Hogan-Howe into one of the most prestigious positions in UK policing as one of his final acts in office. But civil service sources say that any move by Johnson to manoeuvre the former Metropolitan police commissioner into the £223,000-a-year position would be blocked because any candidate first has to impress an independent panel before they make it on to the shortlist of candidates. The recruitment process for the head of the NCA was controversially reopened in May after Hogan-Howe, Johnson’s favoured pick, apparently failed to make it on to the list. Hogan-Howe has broken normal police convention by overtly backing the prime minister, taking the unusual step of supporting Johnson during the 2019 Tory leadership contest. A spokesperson at the Civil Service Commission said Hogan-Howe would need to navigate the same process as his rival for the job, the NCA’s acting director general, Graeme Biggar. “There is due process around making sure that candidates are treated fairly, and go through the same process assessed against the criteria. He will have to be treated like all the other candidates and be assessed against the criteria, through to the appointed candidates list,” said a spokesperson at the commission, which has a mandate to ensure employees are selected fairly. Home secretary Priti Patel has ultimate power over who gets the job. “If the panel, which is chaired by an independent civil service commissioner, decide a candidate does not meet the criteria, they don’t get through to the appointable candidate list for the home secretary to make a decision,” said the spokesperson. The reopening of applications prompted anger, largely because Hogan-Howe, 64, presided over Operation Midland, the Met’s disastrous investigation into an alleged VIP paedophile ring. Concerns have been voiced that Johnson, now effectively a caretaker prime minister in an interim government, does not abuse his powers during his final weeks in No 10. The Tory MP David Davis is among those who have said that important appointments should be left to the next prime minister. Downing Street denies that Johnson has attempted to install Hogan-Howe. • This article was amended on 18 July 2022. An earlier version attributed a quote to “a source” at the Civil Service Commission. This has been changed to refer to a spokesperson for the commission. Also the quote has been amended to more clearly reflect that it was in relation to the appointment process in general.