Voting in tomorrow's Oxford City Council elections will be dominated by national politics, rather than local issues.

That is the view of Mori, the professional pollsters, and councillors who have been pounding the streets chasing votes as the race to control the Town Hall hots up.

Turnout is expected to be between 30 and 40 per cent of voters.

According to councillors in Oxford, the major doorstep talking points have been the well-documented indiscretions of Labour ministers, immigration and the NHS funding crisis.

But Conservative Party leader David Cameron and his Liberal Democrat opposite number Sir Menzies Campbell will also be sweating. Both face their first major electoral tests, with polling taking place across much of England.

Mark Gill, head of political research at Mori, said: "These are the most important local elections for some time, because Labour is in so much trouble and there are two untested opposition leaders.

"But if David Cameron doesn't make a significant impact, people will be asking 'how come you're not making progress?' "Most people don't think councils have much of an impact on their lives, so the national picture is very important."

Labour city councillor Bill Baker, who retires from local politics today said: "I feel worried and concerned about what's happening nationally.

"I have spoken to people who have said 'I'm sorry, Bill. I'm voting Green this time'.

"I think Labour will suffer and I think it's because of what's happening nationally."

Labour has been running the authority, with a minority administration of 21 councillors, but 25 seats are needed for an overall majority.

Liberal Democrat councillor Jim Campbell said: "National issues are important, but in my ward (St Margaret's) I'm fighting neck-and-neck with the Greens and it's entirely on local issues."

Voting takes place between 7am and 10pm tomorrow, with counting taking place at the Town Hall immediately after polling stations close.

Politicians will not be able to use the weather as an excuse for any failures by their parties. The forecast for tomorrow is sunny, with temperatures up to 23C.

Green group leader Craig Simmons is expecting to gain ground.

He said: "There will be a decline in the Labour vote, with some of their supporters not turning out.

"We have a had history of people voting on the national picture in areas where we're strong - issues like the health service and impropriety of some Labour ministers will be important."

Stuart Craft, the leader of the Independent Working Class Association, said: "People are voting for the brand name and, from our experience on the doorsteps, a lot of Labour voters who had a sentimental attachment have finally broken away."

Turnout at the last city council elections in 2004 was 39 per cent - up from 34 per cent in 2002.

* Polling also takes place tomorrow for one third of the seats on Cherwell and West Oxfordshire district councils. There are county council by-elections in the Banbury Grimsbury & Castle and Eynsham divisions, to replace councillors who have retired through ill health and seats on town and parish councils are also up for grabs.