DUBLIN (AP) — Tens of thousands of protesters brought Dublin to a standstill Wednesday in a mass protest against Ireland’s planned new tax on household water supplies, the last major measure in the country’s six-year austerity drive.

Police estimated more than 30,000 people attended the main “Right2Water” rally in the square outside the office of Prime Minister Enda Kenny, where socialist and Irish nationalist politicians appealed from a makeshift stage for the public to boycott their water bills. “No way! We won’t pay!” the crowd chanted. Two of Dublin’s most popular folk-rock singers, Damien Dempsey and Glen Hansard, led the crowd in songs of guitar-strumming protest.

Elsewhere, near the cordoned-off entrance to Ireland’s parliament building, protesters chanting “Whose streets? Our streets!” tried to topple security barriers and hurled objects at police lines. One officer was hospitalized with facial injuries before police reinforcements donning full riot gear spurred the crowd to back off.

As evening rush hour approached, groups of protesters blocked key roads and bridges over the River Liffey, gridlocking traffic for more than three hours and forcing some commuters to abandon their vehicles and walk. An Associated Press reporter saw one protester narrowly avoid being struck by a van, whose driver cursed at him and other protesters as he forced his way past.

Ireland’s 3 ½-year-old government is facing its greatest test since admitting it bungled the creation of a new nationwide utility, Irish Water. The initial deadline for households to register for the new charge came and went Oct. 1 with widespread refusals, and militant crowds have blocked Irish Water workers from installing meters in many working-class neighborhoods. The government, seeking to calm the air of rebellion, proposed smaller, more clearly defined water charges due to come into force Jan. 31.

Right2Water protest leaders vowed Wednesday they would fill Dublin with even more protesters on that day.

The demonstrations coincide, ironically, with the formal end to Ireland’s austerity drive. The government’s 2015 budget contains the first tax cuts and benefit rises since 2008, the year that Ireland’s property-fueled Celtic Tiger boom crumbled amid the global credit crisis. Ireland’s economy is expected to grow more than 4 percent this year amid a revival in job creation and property sales.

Many leading anti-water tax protesters are opposition lawmakers trying to force an early election. Kenny says his two-party government, despite deep unpopularity in polls, intends to run its full five-year term to 2016.