Gordon Brown leads list of MPs who earn most outside Parliament (but he does a lot of good work for charity)

Gordon Brown leads the list of MPs who earn the most outside Parliament but none of the money goes to him personally (EPA)

MPs added to their salaries with outside earnings worth £7m last year, with 20 backbenchers making more money from other activities than from their parliamentary salaries, new research disclosed last night.

The highest earner was the former Prime Minister, Gordon Brown, who declared payments totalling £1.37m in the parliamentary session which ended this month, according to The Guardian. The payments were 20 times higher than the £65,738 salary which he collects as an MP.

His income came from delivering speeches around the world. Mr Brown explained none of the money went to him personally, with £600,000 going to charity and the balance was used to run an office to "support my ongoing involvement in public life".

The next biggest earner was the Conservative MP for Sleaford and North Hykeham, Stephen Phillips, who declared earnings of almost £750,000, which came from his work as a barrister, including some cases which began before the last parliamentary session.

He told The Guardian he was one of the hardest workers in Westminster and argued: "The fact that I don't have a job as a minister and continue to work as a lawyer, mostly when parliament is not sitting and I am not engaged on constituency duties, enables me to keep a foot in the real world – though, I accept, a well-paid one."

Geoffrey Cox, the Tory MP for Torridge and West Devon, declared £417,000 from work as a barrister, while the former Conservative defence minister Nicholas Soames earned £305,000 from a variety of sources including a post as a director of private security firm Aegis Defence Service.

Tory MPs declared more than £4.3m in earnings from outside directorships or jobs, compared with £2.4m for Labour MPs, more than half of which was Mr Brown's income. The former Labour Cabinet ministers Alistair Darling and Jack Straw received £263,000 and £183,000 respectively. There is no ban on MPs holding outside jobs, such as company directorships, as long as they are declared in the Register of Members' Interests and do not entail lobbying Parliament.