More than 20 people are expected to appear in court in the coming weeks in connection with a water charge protest in Tallaght last year in which Tánaiste Joan Burton was trapped in her car for over two hours.

RTÉ News has learned that the Director of Public Prosecutions has directed they be charged with a variety of offences including false imprisonment, violent disorder, criminal damage and offences under public order legislation.

Some are to be charged with more than one offence.

Gardaí commenced an investigation after Ms Burton was trapped in her car, which was surrounded by protesters after she left a graduation ceremony at An Cosán College in Jobstown in November 2014.

Around 40 people were subsequently arrested, including three public representatives and a number of teenagers.

Socialist Party TD Paul Murphy and two Anti Austerity Alliance councillors, Mick Murphy and Kieran Mahon, were among those detained.

After being released without charge, they held a press conference outside Terenure Garda Station during which they accused the Government and the Gardai of political policing.

Paul Murphy also said at the time he had no doubt that he and the other public representatives would be found not guilty of any charge of false imprisonment.

"Let them charge us," he told RTÉ's Drivetime.

"Let them have a jury of our peers because we would be found not guilty, unquestionably."

It is not clear whether those the DPP has directed be charged are to be arrested or summonsed to appear in court.

They are, however, due to face trial on indictment at the Circuit Court, where the penalties on conviction are more severe, as the six-month time limit during which people must be charged to appear before the District Court has elapsed.

Unlike the District Court, where only a judge presides, the cases before the Circuit Court can be tried before a judge and jury.

Gardaí must now act upon the DPP's directions, but it is not clear if those to be charged will be arrested and brought to court, arrested and given station bail to appear in court at a later date, or be summonsed to appear in court.