Rachel Reeves faces questions on Labour donor’s Treasury role

A government spokesperson said: “As you would expect, we do not comment on individual staffing appointments. Any appointments are made in line with the civil service rules on recruitment.”

The Cabinet Office is responsible for codes of conduct for civil servants, ministers and special advisers.

Its Code of Governance says it should be “publicly disclosed” if a successful candidate, has, in the last five years, been employed by a political party or made “significant donations” to one.

According to the code, the sums of money donated by Mr Corfield would count as “significant”.

The Ministerial Code, external says ministers “must ensure that no conflict arises, or could reasonably be perceived to arise, between their public duties and their private interests, financial or otherwise”.

“It is the personal responsibility of each Minister to decide whether and what action is needed to avoid a conflict or the perception of a conflict, taking account of advice received from their Permanent Secretary and the Independent Adviser on Ministers’ interests.”

The Treasury and the Cabinet Office have also been approached for comment.

Ms Trott said: “I just think this is hypocrisy from the Labour Party… They’ve put a Labour donor into the Treasury, into a civil service position, which is meant to be impartial.”

Henry Newman, a former adviser to Michael Gove and Boris Johnson, said: “If Boris Johnson or Rishi Sunak had made this sort of appointment, I can imagine the howls of outrage that would have followed.”

Jack Worlidge, from the Institute for Government think tank, told the BBC the case “exposes the gaps” in the rules surrounding civil service appointments.

He added: “Labour have separately committed to an ethics and integrity commission, which could be a possible route to addressing some of the gaps.”

The Labour Party declined to comment.