Writing in this newspaper last Monday, Peter Robinson said: "…since we were entrusted with the leadership of the unionist community the DUP has been about the business of dismantling the Belfast Agreement and replacing it with a fair deal. That process culminated in the negotiations in St Andrews."

I think it was Mark Twain who cautioned against the gushing enthusiasms of the recently converted and their determination to insist, loudly and frequently, that their newly found belief was the unique be all and end all solution.

Indeed, when Mr Robinson writes that "nobody has a better attainable alternative and people will not listen to those who offer Utopia but can deliver nothing", I am reminded of what I said in this column on many occasions, namely, "there is no viable or available alternative to the existing arrangements and for all their talk of a unionist Utopia around the corner the DUP will end up on the same turf as the UUP".

And here they finally are, on that self same turf. Here, in defiance of Ian Paisley's promise on the eve of the 2005 General Election: "Let me make it unequivocally clear that the DUP will never enter any government with IRA/Sinn Fein.

Note carefully, this is free from any ifs or buts or turnings. To enter into government with the terrorists of IRA/Sinn Fein would be treason. Of that we will never be guilty."

Here, even though they issued a consultation document in October 2006 which stated: "The Government and their counterparts in the Irish Republic have issued the terms of an agreement for the government of our beloved Province. The St Andrews Agreement is the document of the two Governments.

It is not the Agreement of the DUP or any other political party." Odd, then, that Mr Robinson should now suggest that the St Andrews Agreement amounts to the fair deal promised by the DUP; even though the British and Irish governments issued a joint statement saying that "St Andrews underpins the Belfast Agreement and any legislative additions are amendments intended to bolster the existing structures".

Here, so unexpectedly, that Jim Allister has been bellowing from the rooftops at every opportunity that the DUP has betrayed the unionist electorate and "done what it said it would never do". And if the Dromore by-election is a reasonably accurate indication of unionist opinion, then it is clear that a considerable faction of former DUP supporters shares Mr Allister's shock and cynicism.

If, as Mr Robinson claims, the structures of the Belfast Agreement have gone, perhaps he could explain the continuing existence of the Assembly, the Executive Committee, d'Hondt, mandatory coalition, the Programme for Government mechanisms, the North-South institutions and the East-West arrangements? Granted, there have been some tweaks and tinkering around the edges (some of which happened during negotiations between 1999 and 2004); but apart from that the structures are, to all intents and purposes, unchanged. Or, as Dr Sydney Elliott of Queen's University put it: "Given that the underlying principles were the same and that proposals for change were limited by the consensus principle, then the outcome was a modified Good Friday Agreement."

Again, Mr Robinson has over-egged the DUP's pudding with his claim that "today Northern Ireland can have normal neighbourly relations with the Republic of Ireland based on practical cooperation, where our constitutional position is accepted and not threatened".

It was the original 1998 Agreement which secured that new relationship and which built in the removal of Articles 2 and 3. At the time, however, the DUP opposed that Agreement.

And what about his boast that "we insisted on the decommissioning of IRA weapons and required a total end to IRA criminality"? In 1998, the DUP was insisting that decommissioning would never happen and continued to pour cold water over every IMC report which provided evidence that it was happening.

Today, leading members of the DUP are still calling upon the IRA to "end all aspects of their criminality and stand down their Army Council". In other words, the fact that the process hasn't been completed wasn't enough to keep the DUP out of an Executive with Sinn Fein.

Mr Robinson also claims the credit for bringing new accountability into the process. Accountability has to mean much more than the existence of a bloc veto that can be wielded by either the DUP or Sinn Fein.

Accountability means the power to hold a government to account; the power to challenge, amend and vote down a legislative programme; and the opportunity to present the electorate with a genuine choice between an outgoing government and a credible alternative. All the DUP has done is engineer a carve-up between itself and Sinn Fein and created government by absurdly contrived and mostly cosmetic checks and balances. David Trimble's "constructive ambiguity" has been replaced with unambiguous convolution.

I fully understand the DUP's need to persist with the notion that it and it alone is responsible for the supposedly brave new world we now inhabit. That's the way of politics and the party has to find some sort of propaganda to explain the shift of position between 1998 and 2007. That said, the DUP is seriously and dangerously misleading the electorate about the content and nature of what it continues to describe as a "fair deal".

It continues to confuse veto with accountability and it continues with the myth that the Belfast Agreement has gone.

The Belfast Agreement hasn't gone. It remains in situ, amended but un-repealed. And many of the problems with that Agreement (which I have writing about since April 1998) still need to be addressed and resolved. The DUP had a simple choice to make in 2005: tear up the original Agreement (which it had promised to do), or tackle the internal difficulties. It did neither, opting, instead, for an arrangement with Sinn Fein which encourages sectarianism, fuels an "us-and-them" approach to government and shores up veto at the expense of genuine power-sharing.

Peter Robinson and the DUP have a vested interest in persuading the unionist electorate that they did a better job than David Trimble and delivered a genuine alternative to his "odious sell-out".

The facts, however, will cause many people – including many who once voted for the DUP – to reach an entirely different conclusion.