Senior backbenchers are juggling up to nine paid posts outside their MP's work, research by the Yorkshire Post reveals today.

Several former Ministers are among those who will have to reveal how much they earn and how much time they spend on lucrative sidelines.

Publication of MPs earnings on top of their basic £64,766 salary is sure to fuel further controversy in the wake of the expenses scandal. Some Labour figures –including former minister and ex Shipley MP Chris Leslie – have been calling for MPs to be banned from outside work.

Ex cabinet minister David Blunkett, former sports minister Richard Caborn and John Greenway, a Tory frontbencher in the 1990s, each list a series of outside interests earning tens of thousands of pounds on top of their parliamentary pay.

Shadow Foreign Secretary William Hague has been the biggest earner in the region from outside interests in recent years but is now winding down and expects to have quit all his positions and stepped off the after-dinner circuit by the autumn.

The new rules, which are due to come into force on July 1, have infuriated some Tory MPs who claim they are "unworkable" and impractical and claim they are simply designed to embarrass them because more Tories have outside business interests.

Beverley and Holderness MP Graham Stuart accused the Government of an "act of vindictiveness" by pushing through the plans, while Tory frontbencher and farmer Robert Goodwill, MP for Scarborough and Whitby, said voters will be given a "misleading" impression.

The new register is being introduced in the wake of the expenses scandal.

MPs currently have to register outside interests, but do not have to say how long they spend on them. They only have to declare how much they are paid if the job relates to their position as an MP, such as lobbying government departments.

About a third of MPs currently hold outside positions, with almost 100 of them registered as company directors.

The new rules will require full details of pay and hours worked, with at least nine senior Conservatives thought to be planning to quit their outside positions.

Former home secretary David Blunkett, MP for Sheffield Brightside, said he will guarantee working at least 60 hours a week as an MP and he "always endeavoured to give 100 per cent for my constituents", adding: "I will be continuing to fulfil any contractual commitments that I have entered into."

Former sports minister Richard Caborn, MP for Sheffield Central, who registers between £30,002 and £45,000 insisted being an MP was a full-time job.

Ryedale MP John Greenway, a Tory frontbencher in the 1990s, registers income of between £15,000 and £40,000 from positions including President of the Institute of Insurance Brokers and parliamentary adviser to the incentives industry, as well as advising the Tote. He is also chairman of Skills Active Services Ltd, which manages the Register of Exercise Professionals, and a director of Combined Insurance Company of America Ltd.

Huddersfield MP Barry Sheerman, who chairs the influential children, schools and families select committee, appears to be the busiest Yorkshire MP.

Tory Graham Stuart, MP for Beverley and Holderness, said he would observe the new rules but it would be difficult to accurately calculate earnings for many MPs with businesses.

Outside interests of mps in region

Kevin Barron, Rother Valley: Earns up to £5,000 as board member and speaking engagements for Centre for Parliamentary Studies.

David Blunkett, Sheffield Brightside: At least £90,000 from chairing school transport commission, advising global public service reform company A4e Ltd and online payment company UC Group Ltd. Money paid to his company Hadaw Productions and Investments Ltd, but not yet drawn any. Non-executive director of UC Group Ltd, and Tribune Business Systems Ltd. Paid more than £45,001 for articles in the Sun and paid for other articles and speeches.

Richard Caborn, Sheffield Central: Non-executive director, Nuclear Management Partners. Consultant to nuclear construction company AMEC (at least £20,001), Fitness Industry Association (at least £10,001), chairman of Football, Social and Economic Forum (up to £5,000).

David Curry, Skipton and Ripon: Up to £5,000 for Local Government Chronicle column

Robert Goodwill, Scarborough and Whitby: Runs working farm. Also MD and controlling interest in Mowthorpe (UK) Ltd, which operates green cemetery on his land.

Fabian Hamilton, Leeds North East: Honorary president of International Association of Bookkeepers

Eric Illsley, Barnsley Central: Parliamentary adviser to Caravan Club – £5,500

Greg Knight, East Yorkshire: Up to £5, 000 for writing and appearances from Working Men's Club and Institute Union Ltd.

Chris McCafferty, Calder Valley: Parliamentary Patron, Women in Business - Unpaid

Denis MacShane, Rotherham: Paid for journalism and lecturing. Received book advance between £10,001 and £15,000.

John Prescott, Hull East: More than £30,000 for six speeches in 12 months. Between £30,000 and £40,000 last year for TV documentary Prescott on Class, and £50,000 to £60,000 for book Pulling No Punches.

Barry Sheerman, Huddersfield: Seven paid directorships on largely Yorkshire based charities. Paid as member of Environmental Scrutiny Board of waste company Veolia Ltd, and academic adviser to Arcadia University, Philadelphia, USA.

Graham Stuart, Beverley and Holderness: Owner and director of CSL Publishing Ltd.