Ian Paisley has predicted that a combination of dissident UUP supporters, plus the combined strength of his own DUP and Robert McCartney's UK Unionist Party would be sufficient, yet again, for Ulster to say No in the coming referendum on the Belfast Agreement.

It was an outlandish claim in the context of the opinion polls already conducted in Northern Ireland. The formally identified Protestant No vote of 22 per cent suddenly expanded to 56 per cent. But bombast and Dr Paisley are old bed-fellows. And plucking a figure from the air has never daunted a hard-nosed politician.

In many respects, Dr Paisley is now fighting for his political life. His political strategy of remaining outside the Northern Ireland talks process in order to wreck it failed disastrously in the face of government determination and David Trimble's courage.

And his last-minute, late-night protest at the gates of Stormont with only 200 supporters showed him to be a rapidly fading force.

In the circumstances, hyperbole and ballyhoo could have been expected from the ageing founder of the DUP as he sought to reassert his authority. With the future of the DUP and his own leadership at hazard, a traditional, tub-thumping performance was required. And he delivered in some style.

A majority of unionists would unite to defeat the referendum, he predicted, as he sought to enthuse his supporters for the coming campaign. But the battle for Dr Paisley and for Mr McCartney's UK Unionists will be all uphill as the British government and the parties to the talks place their weight behind the agreement.

There is no doubt that a high degree of voter volatility exists in Northern Ireland. Polls, conducted within days of each other, showed how susceptible public opinion can be to uncertainty, particularly within the unionist community.

The Irish Times/MRBI poll, conducted by the Harris Research Centre in Northern Ireland immediately following the agreement, reflected the public euphoria arising from a deal between unionists and nationalists.

Some 73 per cent of those questioned favoured the agreement, with 14 per cent opposed. Within those figures, 93 per cent of SDLP and Alliance Party supporters said they would vote Yes if a referendum on the issue was held on that day. The percentages in favour dropped to 81 per cent for Sinn Fein; 70 per cent for the UUP; 69 per cent for "other parties"; and 30 per cent for the DUP.

Eighty one per cent of middle-class voters favoured the agreement, compared to 69 per cent of working-class respondents. And support was strongest within the 25-to-64 age groups.

In religious terms, 90 per cent of Catholics supported the deal as against 62 per cent of Protestants. In the same context, 3 per cent of Catholics were opposed, compared to 22 per cent of Protestants. A further 8 per cent of Catholics and 16 per cent of Protestants had yet to make up their minds.

Within six days of the agreement, however, old realities began to take hold. When a majority of the UUP parliamentary party opposed the agreement and the Grand Council of the Orange Lodge refused to endorse it, there was a considerable shift by unionist voters into the "undecided" category.

A Sunday Independent/IMS poll found 52 per cent of those surveyed would vote for the agreement on May 22nd, with 13 per cent opposed and 32 per cent in the undecided category.

When the figures were broken down in religious terms, some 78 per cent of Catholics were in support, compared to 34 per cent of Protestants. Support within the SDLP ran at 84 per cent, followed by 71 per cent within the Alliance Party and Sinn Fein; 44 per cent within the UUP; and 13 per cent within the DUP. Opposition stood at 50 per cent within the DUP, 10 per cent within the UUP and less than 5 per cent within the Alliance Party, Sinn Fein and the SDLP.

BUT the level of undecideds had grown enormously, reflecting uncertainty and disagreement within both unionism and nationalism. Some 45 per cent of UUP supporters were unclear about their voting intentions, compared to 38 per cent for the DUP, 25 per cent for Sinn Fein and the Alliance Party and 14 per cent for the SDLP.

Since the Sunday Independent poll plotted the sudden rise in the undecided vote, Mr Trimble has reimposed his authority on the party. And support for the agreement by a massive 72 per cent of Ulster Unionist Council members can be expected to have swung public sentiment back in favour of the document. Sinn Fein has also, effectively, given it support.

But the most significant element in both polls, from the point of view of the governments, is that the level of opposition to the agreement remained static at 22 per cent within the unionist community, and at 12 to 13 per cent overall during a highly-charged, politically uncertain period.

People were prepared to review their positions, but not to the extent of rejecting the document. And since then the tide of events has flowed strongly in Mr Trimble's favour through the decision by the Ulster Unionist Council.

In that context, for Dr Paisley to predict a 56 per cent rejection rate of the agreement among unionist voters is a leap of political faith designed to boost morale among his party workers.

Having failed to prevent a multi-party agreement emerging through abstentionism and obstruction, Dr Paisley is down to the last throw of the dice.

The future of the DUP and his own leadership will be deeply affected by the outcome of the referendum.