Although most MPs are continuing to sun themselves on foreign beaches, the bush telegraph keeps them informed of the latest runners and riders in the Betty Boothroyd succession stakes. Many more phone lines will hum between now and October before a clear favourite emerges. But another set of parliamentary beauty contests will also probably take place in the autumn, with potential consequences for the future of the House of Commons every bit as important as the race for the new occupant of the Speaker's Chair.

Although most MPs are continuing to sun themselves on foreign beaches, the bush telegraph keeps them informed of the latest runners and riders in the Betty Boothroyd succession stakes. Many more phone lines will hum between now and October before a clear favourite emerges. But another set of parliamentary beauty contests will also probably take place in the autumn, with potential consequences for the future of the House of Commons every bit as important as the race for the new occupant of the Speaker's Chair.

I refer to the elections, when Parliament resumes, for the chairmen of the Parliamentary Labour Party (PLP) and the Conservative parliamentary backbenchers' body, known as the "1922 Committee". Clive Soley, the current Labour incumbent, faces several opponents, including Andrew Mackinlay, the delightfully off-message MP for Thurrock, making most of the running so far. In the blue corner, the present chairman of the 1922 Committee, Sir Archie Hamilton, faces the serious prospect of being defeated by Eric Forth, the former Thatcherite minister.

Both Mr Mackinlay and Mr Forth are members, respectively, of the Commons' "awkward squad", who can be relied on to give their own party leaders as much trouble as they give to their political opponents. Each is regarded as a "House of Commons man" and inspire sighs of dread and admiration, in equal measure, whenever they contribute to parliamentary proceedings.

The election of either, or both, by their party colleagues as head of each party's backbench shop stewards' committees (for that is what, in practice, the PLP and the 1922 have become) would be seen as a welcome sign that backbench MPs are finally tiring of the power of the executive and the willingness of both frontbenches to do cynical deals with each other to limit the scope of backbench debate.

Examining first Mr Mackinlay's prospects of defeating Mr Soley, it has to be said that it will not be plain sailing. While Mr Soley is generally seen to have become Tony Blair's representative to the PLP rather than the PLP's spokesman to the Prime Minister, he will probably have the support of the Government whips' office.

Mr Mackinlay also has the prospect of two other likely rivals in the shape of the sacked ministers, Tony Lloyd and Nigel Griffiths. They should not be dismissed. As a junior foreign office minister, Mr Lloyd bore the brunt of Robin Cook's run-in over the Sierra Leone Sandline affair and was the fall guy for his boss. Although Mr Lloyd was probably never going to make the big time, his candidacy will receive support from the softies who think he was badly treated.

Mr Griffiths was a young, sparky consumer affairs minister who fell foul of his civil servants because he had the temerity to stand up to their advice when it was wrong. More importantly, Mr Griffiths is a loyal lieutenant of Gordon Brown and his problems with his civil servants were used as the excuse to remove a key Brownite from the Government in the purge of 1998. Supporters of Mr Brown, whose star continues to be in the ascendant, will want to use Mr Griffiths as a proxy for Mr Brown's longer-term ambitions.

But Mr Mackinlay must, nevertheless, be in with a good chance if he mops up other candidates' second preferences. He was the first Labour MP to break cover from the Millbank pager mentality when he crossed Mr Blair's path with the famous question to the Prime Minister in June 1998, asking for the abandonment of the "fawning, obsequious, softball, well-rehearsed and planted question". More recently he has embraced the demand for the removal of the power of the whips in appointing membership of select committees. This can be expected to garner considerable support from the disaffected Labour MPs who have been kept out of this increasingly important arena.

As a number of Labour MPs with small majorities now toy with the prospect of just seven more pay packets before electoral oblivion, the idea of thumbing their noses at the whips' office also becomes attractive. Mr Mackinlay may well pick up votes from those who think Mr Soley is unwilling to speak up for them when he holds his regular meetings with the Prime Minister.

There are some intriguing parallels across the political divide. In the Conservatives' contest, the prospects for Mr Forth look good. Sir Archie is retiring at the election, so his pitch to be allowed to soldier on for another few months just for his own self-esteem looks weak. Mr Forth previously had a reputation as Michael Portillo's vicar on earth when Mr Portillo was in the wilderness. In an echo of the Griffiths-Brown relationship, Forth's probable challenge to Sir Archie will, therefore, be seen by some as a rehearsal for Mr Portillo knifing William Hague. This is, however, too simplistic an assessment of Mr Forth's objectives.

Of course, if successful, Mr Forth would indeed be the final arbiter of the rules in the event of any hiatus surrounding Mr Hague's future after the next general election. But if Sir Archie wins this autumn, he will be gone anyway after the election, and Mr Hague may still end up with Mr Forth. It might, therefore, be a sensible investment if Mr Hague got used, now, to Mr Forth so that the prospects of a hiatus next year are reduced.

While Mr Forth has had (and may still have) his concerns in the past about Mr Hague's leadership, there is no evidence that he is acting on Mr Portillo's orders or initiative. Indeed, it is not at all certain that the relationship between Mr Forth and Mr Portillo is all that it once was. Far more important is Mr Forth's anger at the official opposition's willingness to connive with the Government on "timetable", "guillotine" and "programme" motions which limit parliamentary debates for backbenchers.

Mr Forth is one of the few to enjoy old-fashioned guerrilla tactics. He has inspired several of the new generation of the 1997 intake Tory MPs. They have only known opposition but they relish the opportunities he provides, through his knowledge of procedure, for hand-to-hand combat with government ministers. Mr Forth's election would be far more worrying for James Arbuthnot, the Tory chief whip, than for Mr Hague. Mr Arbuthnot is sometimes seen as the deputy chief whip of the Government because of the way he spends more time cosying up to Ann Taylor, the Government chief whip.

Mr Forth and Mr Mackinlay both hate frontbench stitch-ups. They are usually to be seen in the same division lobby opposing legislation such as the Football Hooligans Bill. They have sound libertarian instincts on issues such as theright to a trial by jury.

One principal area of difference, however, would be in their attitudes towards the chamber versus select committees. Both pull their weight in the chamber and relish its declining opportunities for debate. However, Mr Forth is determined to retain the primacy of the chamber, while Mr Mackinlay sees the select committees as the primary way to control the executive.

But either way, their election would be a welcome signal that backbenchers care about Parliament.

* mrbrown@pimlico.freeserve.co.uk