SENIOR Tories fear that Tony Blair will have an easy ride over the coming months after Michael Howard's decision to resign plunged the party into its third leadership battle in four years.

Many Conservatives expressed surprise at Mr Howard's intention to quit, despite the party gaining 33 seats in Thursday's election - its first such gains since the 1987 poll.

They fear a renewed bout of party infighting, just as Mr Blair is adjusting to the reality of his Commons majority being slashed from 161 to 66.

Malcolm Rifkind, a former Foreign Secretary and possible leadership contender, said the issue of who would follow Mr Howard was a distraction from the need to determine its policy direction.

Former education spokes-man Damian Green said: "It came as a surprise to many people, including me, that Michael decided to do this now.

"I would have preferred a period of stability.

"I think there's a huge and vital debate to be had about how we reform and modernise the Conservative Party so we can win the next election.

"We have made some progress, but obviously not enough."

In his morning announcement, Mr Howard said he would go "sooner rather than later", but only after the party had decided whether to change its rules for electing his successor.

Nevertheless, the leading contenders - including Mr Rifkind, Shadow Home Secretary David Davis and co-chairman Liam Fox - were expected to start manoeuvring immediately.

It raised the prospect of the Tories turning their backs on Mr Blair as he faces pressure from his own MPs to adopt more "real Labour" policies - and, perhaps, make way for Chancellor Gordon Brown.

Labour left-wingers such as Peter Kilfoyle were quick to predict a different Commons atmosphere, in which it would be difficult to introduce measures such as identity cards.

In Downing Street, the Prime Minister said the fierce criticisms he endured during the campaign had given him a clear idea of what the public expected of his record-breaking third term.

Hospitals, schools, law and order, and immigration would be the priorities of a "radical" programme of legislation, Mr Blair promised.

And a particular priority would be the question of "how we bring back a proper sense of respect in our schools, in our communities, in our towns, in our villages".

Speaking in Putney, one of the seats the Tories snatched off Labour, 63-year-old Mr Howard said he would be "simply too old" to fight another General Election.

He told supporters: "I have said many times since I became leader, during this election campaign, that accountability matters.

"I have said that if people don't deliver they go - and, for me, delivering meant winning the election.

"I didn't do that. I didn't do that despite my best efforts."

The leadership election rules, brought in by William Hague, give the final say to grassroots Tories, who are widely thought to be more right wing than the party's MPs.

After the 2001 defeat, it led to the disastrous two-year leadership of Iain Duncan Smith instead of Kenneth Clarke - the choice of MPs.

Under Mr Howard, the Tories gained 33 Commons seats, but their 197 total is well short even of Labour's 1983 total of 209 - seen at the time as a catastrophic failure.

Before Britain went to the polls, it was widely expected that a minimum of 200 seats were required for Mr Howard to remain as leader.

The Tory share of the vote rose only 1.3 per cent - little more than the 0.9 per cent increase in 2001 - and the party made many of its 33 gains only because the surge in Liberal Democrat support split the anti-Tory vote.

The Liberal Democrats fought off the Conservatives in many southern ultra-marginals, and Mr Howard's party made no inroads at all in Labour's northern heartlands.

Mr Howard's resignation leaves his party needing to decide whether it wants to continue with his populist agenda, with its relentless focus on immigration and asylum.

Many senior Tories had urged the Tory leader to abandon the so-called dog-whistle strategy of Lynton Crosby, the strategist Mr Howard imported from Australia.

The party must also decide whether to risk alienating centre-ground voters by reverting to the fierce tax-cutting agenda favoured by its Thatcherites.

But Shadow Cabinet member Tim Yeo said: "The Conservative Party owes Michael Howard a huge debt of gratitude for bringing us back from the brink of the abyss in November 2003.

"Our survival as the main opposition party was then in doubt, but Michael's professionalism and commitment has ensured we made net gains in a General Election for the first time since 1987."