DUBLIN (Reuters) - Thousands of Irish protesters sent a message to the government at the weekend that next month's referendum on Europe's new fiscal treaty may not be as easy as early opinion polls suggest.
The Irish have tolerated a longer austerity drive than most Europeans but the protests over a 100-euro tax that nearly half all homeowners have refused to pay signals patience may be wearing thin.
That is worrying for the government as it tells voters it is in their interest to support German-led plans for stricter budget rules in a May 31 referendum, that will probably be Europe's only popular vote on the treaty.
The most recent poll showed that 60 percent of voters who had made up their mind would support the new rules. But Ireland's surprise 2008 rejection of the Lisbon Treaty, a set of EU reforms, is a reminder that an upset cannot be ruled out.
Opponents have dubbed the new treaty the 'austerity treaty' and are fighting hard to keep nearly five years of tax hikes and spending cuts at the heart of the debate.
"The discussion quite legitimately will be around Ireland's experience of a whole series of austerity budgets since 2008 and what the consequences are for unemployment rates and the domestic economy," said Mary Lou McDonald, deputy leader of the left wing Sinn Fein opposition party.
"They say that we've been the poster child for austerity across the European Union but we're not Greeks, we're not French. I never really expected that we would have had massive demonstrations on the streets but the absence of those should not be taken as an absence of anger."
Though tens of thousands took to the streets when Ireland's financial crisis began to take its toll in 2009, Saturday's 5,000-strong protest was large by Irish standards.
The government has impressed investors by avoiding the type of riots seen in fellow bailout recipient Greece or the growing dissent stirring in Spain and Italy.
But the Irish economy is back in recession, unemployment is over 14 percent and the government is only halfway through its austerity drive, it seems likely that resistance will increase.
"It's becoming more and more prevalent now, people are not taking it like they did before," Stephen King, a 31-year-old IT worker, said, referring to the recent rise in demonstrations.
"People are seeing it as the government just taxing people who can't afford it... The stress and the strain is showing."
Finance Minister Michael Noonan said at the weekend that he believed "mainstream Ireland" still supported the government. His Fine Gael party, the senior partner in government, is still as popular as it was when coming to power a year ago.
Sinn Fein has become the second most popular party according to recent opinion polls but fellow advocates of a 'no' vote so far only consist of a small group of mostly left-leaning independent members of parliament.
Trade unionists, some of whom marched at the weekend, will decide this week which way to recommend their members vote but the largest unions are expected to join the government's side.
With high profile activists like Declan Ganley, a leading force behind Ireland's 2008 rejection of the Lisbon Treaty, so far staying out of the campaign, analysts are sceptical as to whether Sinn Fein can shift the debate on their own.
"I'm just not sure whether it's going to be doable. While Sinn Fein will try to frame the referendum as an austerity referendum, it won't be any easy thing to do," said Eoin O'Malley, politics lecturer at Dublin City University (DCU)
"Sinn Fein will deliver their vote and a little bit more of people that are angry at the EU and the government but I really don't think they can do it on their own. You'd have to see someone like Ganley and maybe some economists scaring the middle classes. That would be the only way that you'll see a move."
Sinn Fein's McDonald knows it's a tall order but having been among the noisy protesters on Saturday, she says a sea change may come quicker than the government expects.
"As with all EU referendums, it is a David and Goliath scenario because the political establishment have lined up foursquare behind this treaty," she said.
"But I think this is going to be a very tightly contested campaign and I think the household charge will prove to be the straw that broke the camel's back for a lot of people."
Additional reporting by Lorraine Turner; editing by Anna Willard