Analysis By James Hardy BBC Political Correspondent

An independent report expected to recommend a 2.8% pay rise for MPs is to be published on Thursday.

Gordon Brown has urged restraint over public sector pay

The recommended increase is bound to cause controversy among public sector workers who have been forced to accept deals which, because they have been awarded in two stages, amount to 1.9%.

MPs are expected to decide in a "free vote" within the next few weeks whether to accept it or go along with Gordon Brown's call for restraint.

But even if the prime minister gets his way this year there may be trouble ahead because the Senior Salaries Review Body is also reported to be recommending "catch-up" increases of up to 10% over the next three years.

Both the Labour and Conservative leadership - wary of a public backlash - are telling their front benchers to limit their rise to 1.9%. The Liberal Democrats will decide their position on Tuesday evening.

The two big parties are hoping their MPs will follow that lead, but many MPs are already aggrieved at having had to settle for below inflation deals for the past five years.

'Proper' rise

Backbench MPs are currently paid �60,675 a year. Last year they agreed to accept a rise of just 0.66% and that followed two years of 1% rises.

It means that many rank-and-file MPs - who often work up to 80 hours a week when the Commons is sitting - are sympathetic to the argument that they have fallen behind in the public sector pay stakes and deserve a "proper" rise.

One former minister said: "It would be wrong for MPs not to listen to the recommendations of an independent panel which was set up specifically to ensure the issue was dealt with fairly.

"It is no good chopping and changing the circumstances surrounding these recommendations for political reasons."

But other senior Labour figures recognise the potential damage among voters.

Bigger headache

Another ex-minister said: "In general if you have independent adjudicators making recommendations, they should be honoured. Were circumstances better than they are at the moment I would have voted for them - but very reluctantly I've decided to vote against the increase."

The issue has been given added piquancy by the controversial decision to phase the recommended 2.5% police pay award, making it worth 1.9%.

Government business managers are confident they can get sufficient support to peg the pay rise this year to 1.9%, a view shared by the Conservatives.

But privately they admit there is a bigger headache over the two following years. One option under consideration is to split the votes so that this year's rise is dealt with separately.

There is a growing view among MPs of all parties that they should no longer vote through their own pay rises - to avoid the annual "snouts in the trough" accusations levelled by critics.

'Below-inflation'

But because MPs' salaries are paid from public funds provided by the taxpayer it could require a change in the law to alter the arrangement.

Even if the issue was decided entirely by an independent body though, the scope for political controversy would remain.

An independent analysis might well conclude, as the SSRB has done, that MPs' pay has fallen behind people in roughly comparable jobs and propose a higher than politically comfortable rise over which MPs would have no control at all.

An analysis of pay increases circulated to MPs by the House of Commons library shows that since 1990 they have done very well financially.

Over the past 17 years their pay has risen by 127% - compared with a rise in the Retail Price Index over the same period of 72% and a rise in average earnings of 110%.