Senior Conservatives have urged Michael Howard not to step down immediately as party leader.

In the wake of his party's failure to push Labour out of office, Howard announced on Friday that he would vacate the leadership.

The decision came as a surprise, with many party officials and frontbenchers believing he had done well enough to stay on in the position.

Former Cabinet minister Lord Heseltine said Howard should retain his position for long enough to allow Conservatives to reach a carefully considered decision about its future.

"I'm hoping it will be up to 18 months," he said.

"We are going to need a leader who not only can talk to and enthuse the party activists themselves, but can stretch out into that middle area which the Tories have got to capture."

Tory MP Stephen Dorrell said the party needs a leader "who is able to extend [its] reach beyond the 33 per cent of the vote that we have been stuck on ever since 1992".

Shadow home secretary David Davis has emerged as the leading contender to take on the role.

But party co-chairman Dr Liam Fox, another possible candidate, said it was too early to make any decisions.

"We have just come off the back of a general election campaign, where everyone is tired," he said.

"We have got a lot of changes to make to the party's rules, the way that we do business."

Howard had earlier said he was stepping down because "I did not achieve what I set out to achieve".

"I am 63 years old. At the time of the next election in four or five years time I will be 67 or 68," he said.

"I believe that is simply too old to lead a party into government.

"So as I can't fight the next election as leader of our party, I believe it is better for me to stand aside sooner rather than later so the party can choose someone who can."

Howard said he would remain in office until the party had been given the opportunity to determine whether to change the rules for the election of a new leader.