Some 50,000 people packed Dublin’s streets to oppose a government plan for a new water tax. The anti-austerity protest came on the same day as a shock by-election victory for an anti-water charges campaigner, and was Ireland’s largest demo in years.

Until now, Ireland’s citizens paid for their water services through general taxation. However this year, the country’s center-right coalition decided to charge households several hundred euro a year for the service, from the start of 2015. The move immediately became unpopular among the country’s population, and has sparked a mass non-payment movement.

The Right2Water Campaign calling for the water bills to be abolished was organized by trade unions, anti-austerity groups and opposition parties. The organizers of the event estimated up to 100,000 of people took part in the anti-austerity march on Saturday, while the Irish Times put the figure at around 50,000.

State-funded broadcaster RTE, meanwhile, went with a somewhat lower estimate, reporting a police official as saying that 30,000 had participated in the rally.

On the same day as the rally, the results were announced in two parliamentary by-elections. In one, Dublin South West, a leading campaigner against the water charges, Paul Murphy, of the Anti-Austerity Alliance, won a surprise victory ahead of the favourite, Sinn Fein candidate Cathal King.

Both the Anti-Austerity Alliance, led by the Socialist Party, and Sinn Fein oppose the water charges, and together they got more than 60 percent of the votes. Pro-government and pro-water charges candidates saw their share of the vote slashed.

Many commentators saw Murphy’s call for a mass non-payment campaign (a stronger line than that pursued by Sinn Fein) as more in tune with an increasingly angry mood among voters.

South Dublin County Councilor Gino Kenny, of the “People Before Profit” campaign, which supported the anti-water charges protest, told TheJournal.ie that he had not seen such a large rally since 2003 when people protested against the war in Iraq.

“The atmosphere’s great today, so many people have taken part from all over the country. This is just the start of a much larger campaign. We mustn’t lose momentum, this is when people need to stand together,” he said.

All city access routes were blocked by the rally on Saturday.

Working class turned out in force on the 11th. Estimated 100,000 people brought Dublin to a stand still. Right2Water pic.twitter.com/kkpRJ7pA9O — Communist Party Irl (@irelandcp) October 12, 2014

Banners demanding that the government abandon water charges were seen from communities across the 26 counties of the Irish Republic. Some protesters were holding placards, saying “Water for the people, not for profit” and “Ministry of Thirst.”

The protesters were also singing “Enda in your ivory tower, this is called people power,” in a reference to Enda Kenny, the country’s prime minister, and “From the rivers to the sea, Irish water will be free.”

TODAY Saturday 27 September, 2 p.m. March for choice “Speak with your feet” Assemble at Garden of Remembrance (Parnell Square) D 1 — Communist Party Irl (@irelandcp) September 27, 2014

"There is absolute fury against what the government has imposed on the people," Martin Kelly, a rail worker, told Reuters.

"They say this is the last bit, but it's the hardest. People can't take any more," he said, was carrying a placard saying, "Stop the great water heist."

According to Paul Murphy of the Anti-Austerity Alliance, whose election campaign was dominated by a call to boycott the water bills, "Recovery is for the rich, it's for the 1 percent ... it's not for the working class people."

Murphy’s supporters were singing, "No way, we won't pay."

As many as 50,000 marching in Dublin this afternoon against water charges #Right2Waterhttp://t.co/ITvUwqJVMjpic.twitter.com/EVT1MHzgJ0 — The Irish Times (@IrishTimes) October 11, 2014

The water charges were “the last straw,” the protesters told The Irish Times.

“Enough is enough,” said Kathleen McWilliams, a resident from the Artane suburb of Dublin. “The property tax was bad enough, but now I have nothing left to give.”

Tens of thousands of people marched through Dublin city today protesting against water charges http://t.co/8Cxe6bqUrWpic.twitter.com/nDPE6bgGpG — RTÉ News (@rtenews) October 11, 2014

“Will we pay the water charges?” Richard Boyd Barrett, an MP for People Before Profit, asked the crowd. They responded loudly, “No, no, no!”

He called upon the protesters to take part in a further series of anti-water charges rallies around the country on November 1.

“Today we brought Dublin to a standstill. On November 1st we will bring the country to a standstill,” he said.

Dublin city centre - huge turnout on the anti-water charges march. 'Hide your phone, here's Joan' being chanted pic.twitter.com/raZmDM80wA — Colm Ó Mongáin (@colmomongain) October 11, 2014