IT's squeaky bum time. The phrase was coined by legendary football boss Alex Ferguson to describe the nailbiting last few games of the season. But, in the wake of Friday's Irish Times poll on Lisbon, it seems particularly appropriate for the final weeks of the referendum campaign.

It's fair to say a few stomach muscles tightened among Yes campaigners when news of the poll emerged on Thursday night. It wasn't that the poll was disastrous – it certainly wasn't. But to borrow another unforgettable sporting quote, this time from baseball player Yogi Berra, it had an element of "déjà vue all over again".

The poll result, with the slippage away from Yes, had just enough similarities with what happened prior to Lisbon 1 to leave the pro-treaty side a little uncomfortable. Any misguided hopes that the severity of the recession would ensure a stroll for the Yes side can now be put to bed. "It's still all to play for," admitted one senior government source this weekend, insisting they remained "cautiously optimistic".

The negative for the Yes side is obvious. An eight-point drop in the previously rock-solid support for the treaty is high enough to set alarm bells ringing. The doubts that exist in the minds of voters in relation to Lisbon clearly haven't entirely gone away despite the assurances sought and received on issues such as abortion, neutrality, taxation and the commissionership.

And nobody is in any doubt that the hugely negative perception of the government is a factor in the slippage in the Yes support. With a challenging couple of weeks ahead for the government, bringing the contentious Nama legislation through the Dáil, the situation is probably more likely to get worse than better.

However, there remain more positives than negatives in the poll findings for the Yes campaign. For starters, those who have migrated from the Yes side have gone to 'don't know' rather than a definite No.

The gap between the Yes and No sides, at 17 points, is still reasonably large, albeit not large enough to offer complete reassurance. And, perhaps most significantly of all, 91% of Yes voters said they were very likely to vote, but among No voters the figure was just 70%.

In recent EU referenda, the No voters have tended to be more committed but this poll suggests that, given what's at stake, those with a Yes inclination will be more likely to come out to cast their vote. That is what happened in the second Nice referendum, turning the narrow No vote first time around into a comprehensive Yes at the second time of asking.

Friday's poll showed younger voters, particularly those in the 18-24 age group, were also more likely to be in the No camp than older voters, but successive elections have shown that younger voters are much less likely to vote.

It is also true that the No campaign has been more visible to date, most particularly from those highly controversial posters from Cóir. That will presumably change over the next week or so. It needs to.

European affairs minister Dick Roche insists that the poll results were not a shock or a surprise to him. "It demonstrates that the result should not be taken for granted. We're going to have to work very hard. We'll have to listen. We'll have to get out on the streets and combat the negativity and ensure that people have the facts," he told the Sunday Tribune.

Roche believes that one key difference from last year's referendum is that "people genuinely want to know" this time around. "If ever there is a time for effective campaigning this is it."

While he remains confident about the outcome, he insists that a Yes result "depends on whether politicians get out and do the work", adding pointedly that if the British Euro-sceptic party UKIP and Sinn Féin can share a platform, then it shouldn't be difficult for Fianna Fáil, Fine Gael and Labour to "pool our resources".

But in other parts of government doubts linger as to whether or not the main opposition parties will really have the motivation to put their shoulder to the wheel when another defeat would be so damaging to the coalition. "They are talking the talk, but will they walk the walk?" asked one senior figure, adding that while they didn't doubt the commitment of the leadership of Fine Gael and Labour, it remained to be seen if TDs on the ground would respond.

Although the poll has put nerves on edge within the political establishment, there is also a recognition that this might be no bad thing. "It's better this way. People would sit on their arses if they thought it was in the bag. This is a reality check," said one government source.

The Yes side now know what they have to do – the next four weeks will determine whether or not they have the wherewithal to do it. Just like the English Premiership on Easter weekend, the GAA championship in August or the back nine of the British Open, the real Lisbon campaign starts here. The Yes side is still favoured to 'squeak' home but it might be a closer run thing than anyone would have imagined a month or two ago.