By Nick Assinder
Political correspondent, BBC News website
Tony Blair did not change the Labour Party - he created an entirely new party.
That is the view put forward by veteran left-winger Tony Benn and eagerly shared by those who believe "their party" was hijacked by the Blair-Brown-Mandelson "entryists".
And in many senses it is true.
The ditching of Clause IV of the constitution, the ending of the supremacy of the party conference, the huge changes in the way policy is made, the weakening of the links with the trades unions and the abandoning of cherished old policies effectively killed off "Old" Labour.
The move has widely been viewed as an electoral success, moving Labour firmly on to the centre ground and, it is claimed, is now being carbon-copied by Tory leader David Cameron.
He too is trying to cast off much of his party's "nasty" image and create a new centrist Conservative party. Sadly for him, he does not have a symbolic Clause IV to kill off and underpin the shift.
None the less, he is still out to create a modern Conservative party - all soft new logos, redesigned image and centrist policies - just as Mr Blair did when he created a forward-looking, European-style social democratic party and ditched the old adherence to state socialism, which was already on life-support.
The aim was simple. Get rid of all the old left-wing policies like unilateral disarmament, high taxation and nationalisation, reform the party machine and its red-flag image and make Labour less scary to middle England - and never mind annoying the core voters who had nowhere else to go.
The process of changing the party itself had started long before Tony Blair won the leadership in 1994.
Neil Kinnock had certainly wrestled with a revamp of the decision-making processes and attempted to oust the hard-left from the party.
And the reforms were taken further by his successor John Smith, who most famously - and with the help of John Prescott - first broke the power of the union bloc vote.
John Smith, who died in 1994, had started party reforms
Mr Smith's reforms were turned into a virtual revolution when Tony Blair and Peter Mandelson took over after his untimely death in 1994.
Most significantly, by tearing up the very core of the party's old constitution - the controversial Clause IV, which talked of securing "common ownership of the means of production" - Mr Blair was symbolically killing off "Old" Labour.
The clause had long been viewed by many in Labour as outdated and no longer a realistic or even desirable statement of intent.
Others, however, viewed it as a core statement of the party's underlying ideology. Ditching it was, for them, sacrilegious.
But the new leader did not stop there. He instigated a series of changes in the very way the Labour party operated internally, how it related to outside bodies and how it presented itself to voters.
The party conference was completely revamped - some would say neutered - and turned into a consultation exercise with carefully managed debates led by the leadership.
The old days when conference reigned supreme, making policies, often rejecting the leadership's line and even shouting down its own ministers, was brought to a swift end.
The annual Labour conference lost power over policy
There were no more debates where union barons wielding millions of votes decided whether, for example, the party should abandon nuclear weapons.
In its place came the policy forums which sought to open up debate to the wider party and which have regularly been criticised for, in effect, leaving policy-making power firmly in the hands of the leader.
The old system was often misunderstood. The leader always had the final say over what went into, or was left out of, election manifestos unless two-thirds voted for it, for example.
But those conference votes regularly embarrassed and challenged the leadership and handed hostile media a big stick with which to beat the party.
Relations with the unions were also put on an entirely different footing, with "fairness not favours" the order of the day.
Union leaders became increasingly frustrated at their lack of influence and the fact, as they saw it, that the party they created now looked for advice from the likes of the late Roy Jenkins and even Margaret Thatcher instead.
The selection procedures for election candidates were also reformed, allowing the leadership to, in effect, ensure undesirable elements - and that usually meant left-wingers - were kept out and New Labour Blairites were in.
Alongside all this there was the modernisation of the party machine, with the ousting of old party hacks and the introduction of eager young, and frequently temporary, party workers, often looking to make a career out of it.
The red flag went in favour of the non-confrontational red rose, while manifestos became lengthy statements of intent, designed to appeal to Middle England and led by focus groups and pollsters.
Leaving policy to one side, the upshot of all this organisational change was to create a different Labour party.
And it was one that many believe is defined by centralisation.
The question on many lips now, however, is whether New Labour - which once looked for ever - will survive Tony Blair or whether old Labour will make a comeback.