By Nick Assinder BBC News Online political correspondent

Tony Blair will pledge to crank up the pace of public sector reform as he faces a hostile Labour conference in defiant and unbending mood.

The day after he suffered an embarrassing defeat over plans for financing the public services, and was widely attacked over Iraq, he will tell delegates he is not for turning.

Blair's speech main points

Backing the private finance initiative Education in a 'post-comprehensive' era Retain right to bomb Iraq Help victims of crime

His speech - widely billed as the most difficult of his leadership - will seek to win over the conference to both the private finance initiative and to his ultimate goal of dealing with Saddam Hussein.

But he will also make it abundantly clear that he is not about to change tack on either issue.

He will say it is time to press harder for reform of public services, saying "we have not been involved enough" in rejuvenating public services.

Rough ride

It is time to "increase the pace, not mark time or slow down".

Mr Blair is said to consider the welfare state as "monolithic" and in dire need of reform.

The prime minister is expected to get a rough ride from large sections of the conference, deeply concerned over Iraq and public-private partnerships, the two issues which have dominated proceedings in Blackpool.

Mr Blair's aides say he will reinforce undertakings given by Chancellor Gordon Brown that Monday's conference defeats on PFI will be ignored by the government.

And that they will not be allowed to disrupt private sector involvement in the construction of new hospitals and schools.

Serious trouble

The prime minister will also address education and criminal justice reform in his keynote address, which has been billed as "provocative".

While his Thatcheresque "I'm not for turning" message may win over a few doubters it is likely the majority of his critics will remain unconvinced.

And that could land him in serious trouble - first with the unions over the private finance initiative (PFI), and second with many in the Labour movement and the wider public over the best way of dealing with Saddam.

There is the real prospect of escalating action among public sector workers who fear PFI works against their interests and in favour of private enterprise.

The prime minister is already braced for strikes by firefighters and on the railways. And there is even talk of a long winter of disputes.

But Mr Blair is convinced that PFI is the best way of doing that and has to balance the risk of disappointing voters with that of taking on the unions - previously fingered as "wreckers" and "the forces of conservatism".

MPs revolt

Similarly on Iraq, he knows he has a major uphill battle ahead to sway public and world opinion.

The publication of the dossier of evidence against Saddam has done little to change minds and last week he suffered a 50 plus revolt from his own MPs on the issue.

There are also serious worries in Labour ranks about his closeness to the Republican President George Bush.

But the prime minister wants to suggest that, unless he is alongside the president, continually urging the case for caution and the primacy of the UN, Washington may act more precipitately.

Tensions

Many, however, are ready to dismiss that argument, believing instead that when push comes to shove Mr Blair will do the president's bidding.

And, while PFI and Iraq will inevitably dominate, observers will also be watching for signals of the prime minister's intentions on a range of other issues - notably the euro and fox hunting.

The prime minister is expected to acknowledge the A-levels re-grading row but will also say that Britain is now in a "post-comprehensive" era.

Students should go to schools which most accurately reflect their abilities, Mr Blair is expected to tell the conference, signalling the end of comprehensives.

He will also highlight promised reforms to the criminal justice system, with police and courts paying more attention to the needs of the victims rather than criminals.