However, the exact details of what would and would not be allowed remained unclear, with specific changes to the MPs’ code of conduct due to be made public before the end of January. 

The analysis also found that Theresa May’s hourly earnings were the highest at more than £12,500, but she said that most of the £757,520 earned in lucrative speaking engagements would be used to pay employees and to “support my charitable work”. The former prime minister takes home £85,000 from that. 

Jeremy Hunt also registered payments equivalent to £2,000 an hour, but said the money is given to charity. 

Sajid Javid, the Health Secretary, also earned the equivalent of £1,680 for hours worked. He has since left his roles at JP Morgan and C3.ai, an artificial intelligence company. 

Overall, MPs’ additional salary income since January 2020, combined with registered ad hoc payments which cover a slightly smaller period, equate to £7.3 million. Of these, more than half were paid out to just 10 MPs. 

Who are the other high earners?

Other high earners include Fiona Bruce, the Conservative MP for Congleton, who brought in more than £40,000 from her legal firm – although she states much of this is “to meet tax liability” – and Andrew Mitchell, the Conservative MP for Sutton Coldfield, who has earned the equivalent of £328,700 since the start of last year. 

Whilst Conservatives dominate the list, high earners from other parties include Ed Davey, the leader of the Liberal Democrats, who earns roughly £833 for his consultancy work which he says helps support his disabled son. 

Jess Phillips and David Lammy score substantially above the average for other Labour MPs, with both of them earning about £280 an hour. 

Ms Phillips registered £27,997 for two instalments on a book she is writing, for which she clocked 100 hours, as well as various columns.

Meanwhile, Mr Lammy made most of his money on the speakers circuit, talking to clients ranging from Novartis Pharmaceuticals to Facebook.