DRIVING in Northern Ireland can be a complicated business at the best of times. The road signs are confusing and the motorways are punctuated by roundabouts.

But with only one more full day of campaigning to go before the peace agreement referendum, driving is now more than perilous. It is almost impossible.

Pick your route carefully and still you cannot avoid them. The roadsides scream with score upon score of Vote Yes and Vote No posters. They have been unhelpfully plastered across route markers and junction signs throughout Northern Ireland yet, to even the most casual of holiday motorist, they make very interesting reading.

Along the A26, as it winds its way from Belfast International Airport south to the picture postcard town of Moira and further on to the mid-Ulster unionist heartlands of Lurgan and Portadown, are posters bearing the legend: ''It's Right to Say No''.

They are the product of the United Unionists, the minority group led by Mr Ian Paisley - the hulk of a man who, after 30 years of preaching fundamentalist, fire-breathing politics, has styled that negative epithet his own.

Less professional photocopied posters hang lopsidedly proclaiming Mr David Trimble, the leader of the Ulster Unionist Party and die-hard Yes campaigner to be a ''M15 agent''. Another decorated with his image says: ''The Union is safe - so was the Titanic''.

The only sign of a Yes campaign is a smattering of Irish tricolours with the affirmative printed in small black letters.

It is a bizarre state of affairs even by Northern Irish standards. Here we have nationalists preparing to turn out en masse to vote in favour of a document which writes in the maintenance of partition from the Republic, while on the other side of the fence stand a section of unionists ready to say no to the very principle on which their beliefs are founded.

The concept of Mr Trimble sharing a common goal with Mr Gerry Adams remains an almost inconceivable idea to many, but such is today's reality. So why then can so many nationalists accept it, while unionists cannot? Mr David Ervine, leader of the Progressive Unionist Party - the political wing of the Loyalist Volunteer Force and one of the eight parties backing the Yes campaign - thinks he may have the answer.

Speaking from his party's modest headquarters on Shankhill Road, Mr Ervine told The Herald: ''We rather have to determine whether the glass is half empty or half full on the basis there is still a substantial swathe of don't knows after a bombardment lasting a month now of extremely emotive issues.

''People have had to listen to lies, half truths, and unreasonable assertions. If those people who are don't knows are not now in the No camp then they are not going to be.

''If you want my honest opinion - and amateur politicians like myself shouldn't make predictions - there will be a majority in the Unionist community who will say yes come the time.

''It has been suggested there is a lacklustre nature to the Yes campaign. I think those observations are justified but let's look at the Yes campaign and the No campaign and, more importantly, the people who have created these campaigns.

''In the first instance, we have those who skulked out of the talks who then waited in the shadows, sharpening their knives, waiting for an opportunity to pounce.

''Those of us who were trying to go through the pain barrier within the negotiative process did not have the time to devote to campaigns other than the ones that already have a vision for the future of the people of this society.''

Mr Ervine, a former loyalist prisoner who has evolved into a highly articulate political voice, described the Yes lobby as ''a group of very diverse attitudes''.

''It is not hard to look across the gamut of the Yes campaign and see the divisions which perhaps epitomise Northern Ireland and epitomise the diversity and difficulty that is Northern Ireland.

''The people who are involved in saying Yes are essentially the epitome of the Good Friday agreement. They are asking people to put their faith in something which may mean the diversity in our society might one day be celebrated as opposed to being constantly a painful acknowledgment of the existence of others.''

While Mr Ervine talked up the Stormont agreement, Mr Trimble called a press conference to claim the tide had turned towards a Yes vote tomorrow. He said the party's campaign had emerged from a ''wobbly start'' but backing for the Good Friday document could be moving towards 70% at least.

He accused his opponents, Mr Paisley and Mr Robert McCartney, of sneering at the young people who attended Tuesday night's U2 rock concert in Belfast where he appeared on stage with the SDLP leader John Hume in an unprecedented campaign move.

Mr Trimble said: ''They (McCartney and Paisley) have been reduced to telling the most appalling whoppers about this agreement. But it is not working.

''People know they are telling whoppers. Their arguments are being exposed.''

Before going on a walkabout in the centre of Belfast, Mr Trimble said the sour faces of Mr Paisley and Mr McCartney had contrasted with the 2000 at the concert in Belfast's Waterfront Hall.

He asked: ''What future does the 'No' campaign offer? No alternative. No vision. No hope. No achievement. But a 'Yes' vote would give Unionists control over their own affairs for the first time in 26 years.''

Later, Mr Adams said he believed ''50% plus one'' would be a sufficient Yes vote. He accused the No campaign of belonging to the ''old agenda'' and said their days were numbered.

He refused again to declare that the war was over but said: ''The 'Noes' are certainly saying the war isn't over. Let's prove them wrong.''

Along at the PUP office on Shankhill Road, Mr Ervine said: ''Belicose ranting from Unionism won't do the job, we have proved that. There's no future in all getting together, going to a Nuremburg-style rally, singing the Sash and all going home thinking everything is alright - and of course everything is not alright.

''Who would have believed it if I said to you five years ago that there is going to be ceasefires, there is going to be negotiations, there is going to be an acceptance of the universal principle of consent, and that the Provos are going to take their place in an Northern Ireland assembly which recognises the partitionist nature of Northern Ireland? You would have said 'It's Carstairs for you, my boy'.

''But we're going to do that and if we can achieve that we can achieve anything. I firmly believe that in another five year's time, people will look back with a prosperous hindsight and ask what all the fuss was about.''