Analysis By Nick Assinder Political correspondent, BBC News website

David Cameron travelled to Blackpool for the Tory conference with two huge question marks hanging over the event.

Mr Cameron needs to reassure party it can win

Will the prime minister blow it out of the water by announcing an autumn general election?

And, with the Brown bounce refusing to flatline, can the Conservative leader do anything to get his own leadership back on track and his party into election contention and delay an autumn poll?

On the first, Gordon Brown is more likely to wait until after the Conservative conference before he makes up his mind on a snap poll - assuming he hasn't already done so.

He will want to see how Mr Cameron does, how rebellious or otherwise the Tory grassroots are and what the polls do in the immediate aftermath of the rally (all leaders get a poll boost after their conference speeches).

In any case, the only impact Mr Cameron can have on the prime minister's decision is by ensuring he answers the second question with a resounding "yes" and, as a result, gives Mr Brown reason to think again about a snap election.

The noises off before the Conservative conference were not too good for Mr Cameron.

Strong leader

Former party chairman Lord Tebbit heaped praise on Gordon Brown and sniped at Mr Cameron's decision to deliberately distance himself from Margaret Thatcher. He, along with others, have set Mr Cameron the challenge of stopping Mr Brown's election plans in their tracks.

And former leadership contender Michael Portillo warned Mr Cameron there would be great tensions at the rally and that he needed to show he was as strong a leader as Gordon Brown.

Lord Tebbit has criticised Mr Cameron's leadership

Mr Cameron, however, believes he has some aces up his sleeve.

One is his pledge to offer voters a referendum on the new EU reform treaty - something Mr Brown has ruled out.

That is mirrored by a campaign in the Sun newspaper and may even help to win owner Rupert Murdoch's support in the event of a general election.

He also has the results of his six policy review teams on everything from social responsibility and mending the broken society to green taxation and the family.

Shadow ministers are expected to offer the first signs of which of these proposals will find their way into the party's election manifesto.

Liberal ideas

Mr Cameron has already done his "laying the foundations" conference - this time he needs to show the building is nearing completion and is planted firmly on the centre ground.

He desperately does not want to see more sniping from his traditionalists pressing for a return to more right-wing policies on issues like immigration, taxation and Europe.

They fall into two broad groups - those who have never supported him and have been eager to say so, and those who have simply gone along with him in the belief he was a winner.

If the second group starts believing he does not have the victory gene they may very quickly begin looking elsewhere.

Mr Cameron has promised a referendum on EU treaty

One of the, presumably unintended, consequences of Mr Brown's early election tease is that rebels may keep quiet for fear of undermining their chances in that poll.

So, Mr Cameron needs to see a united party adopting some concrete, distinctive and popular policies and showing it is not only prepared for a general election, but eager to get stuck into the government.

Perhaps most importantly of all, Mr Cameron needs to give voters a clearer idea of exactly what sort of prime minister he would make.

More of same

He has faced criticism for appearing as a Blair-lite candidate at a time when, as Gordon Brown's popularity seems to suggest, voters want something a bit more solid and worthy.

There were some hints of what he plans at the conference in the speech he delivered to the Carlton dinner a few nights ago.

HAVE YOUR SAY Love him or loathe him, no-one can deny that Cameron's ideas are original George Madden, Birmingham Send us your comments

He told the gathering that, in the 1970s the problem was irresponsible unions, today it was irresponsible parents. Then it was inflation, now it was crime.

"Opportunity, responsibility and family" were the new Conservative watchwords, he said.

He also indicated his line of attack on Gordon Brown would be to remind people that he had been jointly responsible, with Tony Blair, for all the government decisions over the past decade.

A vote for Gordon Brown, he said, was a vote for more of the same.

It is clear, and was stressed during his Sunday morning BBC interview with Andrew Marr, that his goal is to persuade the country that only the Conservatives can give voters "the real change the country wants".

It is a theme he will reflect in his big conference speech on Wednesday.

Two years ago he all but won the Tory leadership against the odds thanks to a party conference speech - the question is whether he can repeat the trick this time with the highest office in the land.