David Cameron's first months as Conservative leader will be judged on local election results in cities such as Birmingham and Coventry, Tory strategists said yesterday.

But they were eager to play down expectations and admitted they could not be sure of retaining control of authorities such as Birmingham.

Mr Cameron, who won the leadership in December, has vowed to win back Tory support in cities, and attention will focus on his party's performance in metropolitan areas in the May 4 elections.

Aides pointed out Tories were effectively starting from scratch in cities such as Manchester, Liverpool and Newcastle, where they have no councillors.

However, they accepted the same could not be said in the West Midlands. Birmingham is run by the Conservatives in partnership with the Liberal Democrats, although Labour remains the largest single party. Coventry is also run by the Tories, although no party has a majority. The Tories have overall control of Dudley and Walsall. One third of seats will be contested in all these authorities.

A Conservative spokesman said the Tories could not be certain of hanging on to councils such as Birmingham.

"There may be issues across Birmingham that lead to a swing across the whole city. I always try to steer away from predictions but I think people in Coventry, Dudley, Birmingham and Walsall have seen the benefits of having a Conservative-controlled council."

About 4,360 council seats, a fifth, are up for grabs this year, predominantly in urban areas.

Local government experts have warned the Tories may not enjoy any "bounce" effect from Mr Cameron's new leadership.

If the Conservatives fail to make headway, critics are likely to brand Mr Cameron's attempt to reach out to new voters a failure.

But his task is harder because the Tories are already the largest party in local government, with 7,960 seats and 157 councils compared with 5,538 seats and 71 councils for Labour. Party chiefs are also sceptical about suggestions the Liberal Democrat vote could be hit by recent scandals.

A spokesman said: "We have never taken the view that the Liberal Democrats are set for a poor performance in the local election.

"Local candidates are less affected by their national standing than you might imagine.

"We intend to make gains from them, but I don't think it is realistic to expect them to collapse."

The Liberal Democrats suffered a series of setbacks when former leader Charles Kennedy resigned because of a drinking problem, leadership contender Mark Oaten admitted an affair with a male prostitute and another contender, Simon Hughes, said he had concealed being gay.