EXPOSED: Public sector rich list blows lid on the 120 civil servants earning tens of thousands more than PM

The thinktank found the Civil Service salary bill has skyrocketed by £6.1billion over this period, excluding extra costs such as national insurance, pension and other benefits.

Of that rise, more than £2billion comes from many employees being moved into higher-level roles, which equals higher salaries.

The report further revealed that 120 civil servants now earn more than the Prime Minister, with thousands earning over £100,000 a year.

Some senior public sector figures, including those overseeing HS2 and the Bank of England, are said to be receiving salaries exceeding £500,000.

A "rich list" compiled by Facts4EU found the average salary for those working in the Civil Service overall was £292,500 (see chart below).

The average salary was found to be the same figure for those working specifically for the Ministry of Defence.

Veteran Conservative Sir John Redwood said: "The latest public sector rich list shows there are now many public sector employees paid more than the PM.

"Several who preside over making heavy losses for the taxpayer running HS2, the Post Office and the Bank of England are paid more than £500,000.

"These posts should with future hirings pay a basic salary around the level of the PM with bonus opportunities for much higher pay if they deliver.

"The Bank should have to deliver its inflation target and avoid all losses.

"The Post Office should make a profit. HS2 should deliver on time and to budget."

The report also shows that while lower-grade roles such as Administrative Officers and Assistants have declined as a proportion of the growing workforce, the number of higher-rank jobs have increased.

This serves to potentially challenge claims that Brexit was the main driver behind the 25 per cent rise in staffing.

If Brexit had required more administrative capacity, Facts4EU argues, there would have been growth in more junior roles.

Instead, the opposite has occurred, with senior grades making up a larger share of the workforce.

Sir John added: "It is difficult to see why there has been so many promotions in the civil service in recent years.

"The civil service does not need more managers. It needs better management.

"The more managers it has appointed the worse the long delays in getting answers, the long waiting lists in the NHS, and the long waits to settle migration cases have got."