Tens of thousands of protesters have brought Dublin to a standstill 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 on Wednesday in the square outside the office of Prime Minister Enda Kenny, where socialist and nationalist politicians appealed from a makeshift stage for the public to boycott their water bills.

"No way! We won't pay!" the crowd chanted.

Elsewhere, near the cordoned-off entrance to Ireland's parliament building, protesters tried to topple security barriers and hurled objects at police lines. One officer was brought to hospital with facial injuries before riot police 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.

'Already paying'

Until now water in Ireland has been paid for out of basic taxation. But the government says infrastructure needs a massive overhaul and the people should stand the cost.

"The government has misspent our money," opposition politician Daithi Doolan told Al Jazeera. "They've chosen to bail out bondholders, rather than investing in an essential service that we pay for. People on this march, people in this city, already pay for the water. They pay every day out of their taxation and have done so for 200 years."

The initial deadline for households to register for the new charge came and went October 1 with widespread refusals, and crowds have blocked Irish Water workers from installing meters in many working-class neighborhoods.

The government, seeking to calm the opposition to the tax, proposed smaller, more clearly defined water charges due to come into force January 31.

The minister responsible for the water charges, Environment Minister Alan Kelly, described the protest as "a significant day" but insisted there would be no further climbdown.

"The package that has been put forward is the best package that is available. The majority of reasonable people have come with us in relation to this," Kelly told reporters.

The Irish economy has revived since exiting an EU-IMF bailout a year ago and is forecast to be the fastest growing in the EU this year, but many people have yet to feel the benefits with unemployment still well above 10 percent.

Source: Al Jazeera and agencies