Michael Howard has hit the by-election campaign trail as a poll shows a slump in his support.

The Conservative leader was campaigning in the Birmingham Hodge Hill and Leicester South constituencies on Friday ahead of ballots there in less than two weeks.

The Tory chief is keen to improve on his party's poor showing in the Brent East poll last year, achieved under his predecessor Iain Duncan Smith, but faces a stiff challenge from both Labour and the Liberal Democrats.

The Tories were humiliatingly beaten into third place in Brent and Howard will want to show that he has has made a difference to his party's standing in the country.

But a MORI survey taken over the last week revealed that his honeymoon period appears to be over.

The poll showed 38 per cent of voters saying they were dissatisfied with Howard, up from 31 per cent in May and 22 per cent in the first few months of his leadership.

The pollster also puts the Conservatives on 31 per cent in general election voting intentions, a long way short of where they will need to be even to make gains in an election likely next May.

MORI chairman Bob Worcester said Howard's confident style was beginning to grate with voters.

"What's happening is that the don't-knows are making up their minds... and he's not coming across well," he claimed.

"My speculation would be that it's because he is strident and, perhaps, too clever at the despatch box."

Howard will hope to show a more likeable side of his personality with a series of appearances on lifestyle shows in the next week.

He and his wife Sandra, a former model, will appear on the This Morning show on ITV having first selected his "Desert Island Discs" for BBC Radio 4 where he can be expected to reveal his love of 1950s and '60s rock and roll.