The public administration select committee wants to investigate how the business world uses MPs to lobby on its behalf.
It has called Labour's Ian McCartney, Tory John Greenway and Liberal Democrat Nick Harvey to appear on Thursday morning.
McCartney, a former trade and industry minister, has attracted negative coverage for his conncection with Fluor, one of the world's largest nuclear companies.
He is paid £115,000 a year for advising the US multinational, which is currently bidding for a £5 billion contract to run Sellafield, Britain's biggest nuclear site.
According to the House of Commons Register of Members Interests, Greenway receives at up to £10,000 as a ‘consultant to the Tote, providing advice on public policy in relation to horseracing'.
He has also registered up to £15,000 from the Institute of Insurance Brokers.
Meanwhile ex-PR man Harvey receives up to £10,000 from PR agency Trimedia for being a ‘communications strategies consultant'.