Michael Howard has brushed aside a wave of criticism of his performance as Conservative leader.

Speaking on Monday, he said the issue was something "that crops up from time to time".

Recent doubts were exacerbated at a weekend when a poll suggested the Tories were level pegging with the Liberal Democrats.

And former party leadership contender Michael Portillo said Howard had "broken his own bat" by appearing to change his mind on the justification for the Iraq war.

But at an environmental policy launch, the Tory leader downplayed the recent doubts, saying the can come and go for party leaders.

"It's not the first time and I'm sure it will not be the last," he said.

And asked if he would still be leader after the next general election, Howard added: "I very much hope to be prime minister."

Meanwhile, other senior party figures have also rallied round.

Dismissing "idle chatter", shadow environment secretary Tim Yeo said the current leader had knocked the Conservatives into "vastly better shape".

"I remember what last summer was like. It was a nightmare of dissent," he added.

And shadow chancellor Oliver Letwin said: "I am absolutely confident that Michael Howard is the person who deserves to be, and I believe will be, the next prime minister of this country.

"What Michael Howard has done for the Conservative Party is to give us a huge new sense of working together and he has also given us a sense of strategy."