By James Landale BBC political correspondent

The Liberal Democrat leader is also considering forcing Simon Hughes to give up his home affairs post so he can concentrate on his campaign to replace Ken Livingstone as London mayor next year.

The Lib Dem leader will spend this weekend working out the new shape of his team for the next election

Mr Kennedy carried out a modest reshuffle of his frontbench twelve months ago but most of his shadow cabinet have stayed in the posts they were given after the last election.

The Lib Dem leader will spend this weekend working out the new shape of his team for the next election.

He is expected to announce the results in two weeks before MPs return to parliament on 14 October after the party conference season ends.

Mr Kennedy has been helped by two voluntary departures. Jenny Tonge is stepping down as international development spokesman so she can help her successor at Richmond Park, Susan Kramer, stop the Tories seizing the seat at the next election.

Kennedy is expected to plan changes this weekend

Nick Harvey, who stood against Mr Kennedy for the party leadership, is standing down as the culture, media and sport spokesman so he can spend more time with his young family.

One possible replacement for Dr Tonge is Michael Moore, the deputy foreign affairs spokesman, who is considered to have performed well during the war when Menzies Campbell was off sick.

Headache

Another possibility could be Norman Lamb, a treasury spokesman. There are no obvious front runners to take over the culture portfolio, although there has been some speculation that Sandra Gidley, MP for Romsey and spokesmen for women, could take on the role.

Mr Kennedy's biggest headache is what to do with Simon Hughes. He was widely expected to stand down as home affairs spokesman after he was elected the Lib Dems' candidate for the London Mayoral elections next June.

A close aide said Mr Kennedy hadn't yet decided whether or not to sack Mr Taylor and made clear that such a move was "in play"

But Mr Hughes has shown every sign that he wishes to hold onto the home affairs portfolio. It is a high profile post which gives him wide media exposure.

He is also thought unwilling to hand the job over to someone else and potentially be left without a role next year if he fails to beat Ken Livingstone.

However, there is a feeling among some MPs - and aides close to Mr Kennedy - that Mr Hughes should give up home affairs so he can exploit the party's increased popularity in the wake of the Brent East by-election.

If Mr Hughes is forced to give up home affairs, his most likely successor is Mark Oaten, the party chairman. One MP said that after a succession of party jobs, it was time Mr Oaten had "a proper job in the House of Commons".

The second problem is what to do with the Treasury team. Some MPs believe that Matthew Taylor has not performed well against Gordon Brown.

The likelihood is still that Mr Kennedy will balk at sacking his old friend and former leadership campaign chief.

But a close aide said Mr Kennedy hadn't yet decided whether or not to sack Mr Taylor and made clear that such a move was "in play".

Ruffled feathers

Another senior adviser, when asked about recent press attacks on Mr Taylor, replied that "it makes it all much more difficult for Charles to sack him".

If Mr Taylor does go, his most likely successor is said to be Vincent Cable, the DTI spokesman and former chief economist for Shell, or Ed Davey, the local government spokesman and former management consultant.

Reports that David Laws, the young Shadow Chief Secretary and former senior currency trader at the BZW bank, would replace his boss are wide of the mark.

A source close to Mr Kennedy said that Mr Laws, an extremely bright economist, had ruffled feathers with his abrupt style and free-market economics.

One senior MP said any promotion for Mr Laws would be unpopular within the party: "David has rather sharp elbows. He needs to do his time first."

Happy

The third issue is what Lib Dem MPs call "the producer problem". There is a perception that the party is not performing well on health and education because its spokesmen covering those areas are too close to the NHS and the education lobbies.

Evan Harris, the health spokesman, is a doctor; Phil Willis, the education spokesman, was a teacher. Some MPs believe both men - both on the left of the party - call too easily for more tax rises to keep their respective public sector lobbies happy.

One MP said he doubted if Mr Kennedy "had the balls to sack the people who needed to be sacked"

One suggestion doing the rounds is for Mr Kennedy to do a straight swap and send Mr Harris to education and Mr Willis to health.

Another issue for Mr Kennedy is what to do with Don Foster, his transport spokesman, who is known to be keen to move on to another job.

It is understood that he would like to be chief whip, although that post, currently held by Andrew Stunell, is an elected position for the whole of a parliament and will therefore not be available until the next election.

Charles Kennedy has a history of modest reshuffles, preferring incremental change to bloody culls. One MP said he doubted if Mr Kennedy "had the balls to sack the people who needed to be sacked".