By Nick Assinder BBC News Online political correspondent

The first day of the Labour Party conference was dominated by speeches warning rebellious delegates to unite behind their leader.

Party Chairman Ian McCartney and Commons leader Peter Hain both delivered similar messages.

What they amounted to was: "Carry on the way you are going and you will throw us back into the political wilderness."

Mr McCartney's speech even recalled the traumatic conference in the same venue 18 years ago when then leader Neil Kinnock took on the Militants with a barnstorming assault.

This was a calculated attempt by Mr McCartney to remind the delegates where years of in-fighting had left them in the past - with 18 years of Thatcherism.

Left wingers

His references to the "rabble which was junking the values and aspirations that brought this party into being", seemed particularly designed to infuriate the government's critics within the Labour party.

Only the day before, Health Secretary John Reid had echoed Tony Blair's words by branding the rebels "conservatives".

The implications could not be more clear.

The message these speeches were sending out was that another "rabble" of left wingers were leading the attacks on policies on Iraq, public services, tuition fees and the like.

Usual suspects

They must be stopped before they led Labour to electoral defeat and handed power back to another right wing Tory party.

And, of course, Tony Blair - who had already insisted he was not for turning on controversial policies and had no regrets over the war - is the man to do it.

There is another leader in the wings

But to liken the government's current critics to the Militant Tendency is hardly designed to calm things down or win over the critics.

It appears the prime minister is planning a bare knuckle knockdown fight with his critics.

That carries no small risk. While some of those leading the attacks are indeed the "usual suspects", and there is a new breed of left-wing union leaders refusing to toe the line, a large section of the internal opposition are loyal Labour members.

Make or break

They will not take kindly to being branded conservatives or a rabble.

How they react to these challenges will be the story of this conference.

Certainly, these same delegates will take seriously the warnings of allowing a Tory revival.

But they also know there is an alternative - entering the next general election with a different leader.

And so, once again, all the conference focus comes back to that one issue of Tony Blair's leadership.

If the opening day is anything to go by this is not going to be a kiss and make up conference.

Indeed, for the prime minister, it has all the hallmarks of a make or break rally.