Two gardaí were injured during a two-hour stand-off with water charge protesters who blocked the Tánaiste’s car in Jobstown in Tallaght yesterday.

A Garda spokeswoman said two officers required medical treatment after the incident and described the injuries as “non life threatening”.

Gardaí were called to the An Cosán College at 1pm yesterday when up to 100 protesters surrounded and blocked Joan Burton’s car by sitting in front of it as she was leaving a graduation ceremony.

The Tánaiste was trapped in her car for a period. When additional gardaí arrived, including the Garda Public Order Unit, Ms Burton was transferred into a Garda car which was escorted by gardaí through the crowd of protestors.

During protests eggs and bottles were thrown and some images from the protests appear to show gardaí using pepper spray.

Two men in their late teens were arrested in connection with the incident. One was detained over criminal damage to a garda vehicle and the second for a public order offence.

Independent Senator Katherine Zappone, a co-founder of An Cosán College where Ms Burton was visiting, said she witnessed much of the protest and described the "menacing nature" of the demonstrators as unacceptable.

“The actions of some of the protestors generated an air of intimidation and menace which turned what should have been a local community celebration into a major security operation, with the Garda Public Order Unit on the ground and a helicopter overhead,” she said.

“The blockading and banging of posters on the Tánaiste’s car, the jostling and spitting at those involved in the event goes beyond any legitimate form of protest.”

Minister for Communications Alex White, Ms Burton's Labour colleague, told RTÉ that it was "anti-democratic" to block somebody in such a way. He was critical of Mr Murphy, saying the incident was not consistent with the principle of socialism.

A spokesman for Ms Burton said she had attended a graduation ceremony at an Cósan higher education college. “Nothing should be allowed detract or deflect from what was a very important day for those students,” he said.

Socialist Party TD Paul Murphy, who participated in the demonstration, said the protest, which began shortly before Ms Burton attended the ceremony at noon, had been peaceful.

He said the Tánaiste had been delayed for a number of hours but “I think this protest has sent a very clear message to her, a message which the Tánaiste has ignored to date, that that people don’t want to pay these water charges”.

"There is national anger over the changes but particularly in Tallaght and Jobstown in west Dublin...there are a lot of people who simply can't afford to pay," he said, adding the protesters were also sending a message to Irish Water that the people of Tallaght would not accept water charges.

The protests come two weeks to the day after over 100,000 people marched against the introduction of water charges in cities, towns and villages across Ireland including tens of thousands of people who turned out in various locations in Dublin.

Public anger over the proposed charges has led the Government to propose a much simplified system of water charges which will result in an effective annual charge of less than €200 per household.

The Coalition parties hope that this reformed package, which is due to be finalised in days to come, will be enough to encourage a majority of households in the State to register with Irish Water and end the ongoing controversy which the proposed charge has generated.

The revised plan would see the discarding of multiple tiers of charges based on the number of adults in a household. It will also replace three separate water allowances with a single universal allowance.

Under the scheme, every household which registers with Irish Water and gives details to the Department of Social Protection will be entitled to an annual allowance of some €100.

The single allowance will be available to all households irrespective of means. It will replace the tax concession included in the budget, and other allowances announced as part of the social welfare package.

There will also be a simpler charging model, based on only two rates. The first rate will be for a single-adult household and the second for a household of two adults or more.

Referring to the expected proposals on Thursday, Taoiseach Enda Kenny said the Government had “listened very carefully to the concerns and anxieties of the people.”