The main choice, between the "restraint" of a 3 per cent rise and the independently-assessed "fair" rise of 26 per cent, has been complicated by the Senior Salaries Review Body's proposal to cut generous car- mileage allowances.
With both Conservative and Labour front benches urging restraint, Government whips last night predicted a close vote, with some predicting that MPs would vote to accept the review body's pay rise and keep mileage allowances as they are - the most generous option available.
This would add pounds 9,000 to MPs' present pounds 34,000 salary, with a separate vote on bigger increases for ministers, taking the Prime Minister's salary up pounds 60,000 to pounds 143,000.
But many MPs earn a significant amount of tax-free income from ample 74p-a-mile mileage allowances, which the review body's recommendation is asking them to give up for a similar amount of taxable salary.
Michael Stern, a Tory MP and accountant who handles the tax affairs of several of his colleagues, said that some of them would be worse off on balance if the full review body package were implemented.
Chris Mullin, the Labour MP who has campaigned against a inflation-plus increase for MPs, said he knew that some of his colleagues drove to and from their constituencies in order to earn money to subsidise their constituency and Commons offices. But others simply regarded it as a perk which made up for what they regarded as inadequate basic salaries.
Further complexities have been added to tonight's open-ended succession of votes by a series of amendments tabled overnight on issues ranging from pensions to outside earnings. The 120 government ministers, whips and aides are under instruction to vote for the 3 per cent increase, but many are expected to absent themselves.
Paddy Ashdown, the Liberal Democrat leader, has also favoured 3 per cent. But the 80 frontbench Labour MPs are likely to split over Tony Blair's lead in urging a vote for restraint. Up to nine members of the shadow Cabinet resisted attempts by Mr Blair to persuade them to vote for 3 per cent.
The inquiry by the Senior Salaries Review Body was set up by the Prime Minister in February after 298 MPs of all parties signed a motion calling for an independent review. The body's report, published last week, said a pounds 9,000 increase for MPs was justified on grounds of "international comparability, heavy parliamentary workloads, increased lobbying and constituency expectations, and the need to attract able candidates". The exact figure was set simply by uprating the 1983 recommendation of pounds 19,000 a year, which was reduced as a voluntary act of pay restraint.
As for ministers, whose higher recommended increases would not come into effect until after the election, the review body says: "We believe that additional recognition of the job weight of the Prime Minister and Cabinet ministers is long overdue."Reuse content