Although the Chinese firm they thought they were meeting was fake, the footage has sparked scrutiny of MPs` earnings outside the House of Commons.
And analysis of official data by Statista for The Independent shows that British MPs earned more than £7 million in total outside their parliamentary wages last year, with Tories accounting for the largest proportion.
Conservative Party politicians collectively earned £4.74 million, more than double the amount of Labour MPs, although there were more Tory MPs when the figure was compiled.
The findings have sparked calls from Ed Miliband for payments outside Parliament to be capped but by far the biggest earner was one of his party`s own MPs, former Prime Minister Gordon Brown, who was paid a total of £962,516 in 2014 on top of his parliamentary wage.
Mr Brown earned £61,730 for one two-and-a-half hour speech for the First Dameisha China Innovation Forum in Beijing and another £46,500 for speaking at The American University in Dubai, public records show. He holds posts including
Distinguished Global Leader in Residence at New York University,Chairman of the World Economic Forum Policy Coordination Group and United Nations Special Envoy for Global Education and also earns fees for newspaper columns and books.
Mr Brown states that he does not personally receive any of the money, which a public register of MPs’ earnings states is “being held by the Office of Gordon and Sarah Brown to support (his) ongoing involvement in public life”.
The second-biggest earner outside the Commons was the Conservative MP for Torridge and West Devon, Geoffrey Cox.
He took home an extra £820,867 last year, mostly through his work as a top lawyer at Messrs. Janes solicitors. Almost 2,000 hours of outside work were logged, making an average hourly rate of £420, or £20 every three minutes.
The figures suggest Mr Cox works an average 40-hour week as a QC rather than in his political role, but in response to criticism last year he put the figure at 15-20 hours per week, saying the "majority is done at weekends or during parliamentary recesses".
Respect MP George Galloway earned more than £300,000 extra, mostly from his regular £1,600-an-hour appearances on Iran`s Press TV and Russia Today.
Winston Churchill’s grandson, Sir Nicholas Soames, earned £275,500 for posts at controversial private security firm Aegis, energy firm Aggregated Micro Power and as a business adviser.
Former Labour Home Secretary David Blunkett received almost £180,000 on top of his Parliamentary wage, mostly as a director of Hadaw Production and Investment Ltd.
All MPs in the top 10 earned more than £178,000 extra last year. That figure alone is higher than the David Cameron’s entire annual earnings of £142,000 for being Prime Minister.
With the exception of Mr Cox, the highest earners were not the MPs who did the most hours of paid work outside their political office.
Stephen Dorrell, the veteran Conservative MP for Charnwood, put in 1,700 hours as the director of a management firm and in various consultancy work.
William McCrea, a Democratic Unionist Party politician from Northern Ireland, was the only other MP putting in more than 1,000 hours of extra work last year as a Free Presbyterian minister.
The 10 MPs who logged the most hours of extra work last year were all male. Eight were Conservative politicians, one was Labour and they collectively put in 9,089 hours.
Embattled former Foreign Secretary Sir Malcolm, who is embroiled in the “cash for access” scandal after being filmed claiming he could arrange “useful access” to every British ambassador in the world because of his status, did not feature on the top lists.
He has since resigned as an MP and as head of the highly influential Intelligence and Security Select Committee after the whip was withdrawn by the Conservative Party.
In the sting, he said: “I am self-employed. So nobody pays me a salary, I have to earn my income.”
Public records show Sir Malcolm declared payments of £69,610 for 43 hours of work - an average £1,619 per hour – for directorships, consultancy, speeches and newspaper articles.
Defending his secretly filmed comments, Sir Malcolm said it was “unrealistic” to expect MPs with a business or professional background “to simply accept a salary of £67,000” and they are rightly allowed to continue other employment.
