Solidarity TD Paul Murphy has pleaded not guilty to falsely imprisoning the former Tánaiste Joan Burton in Jobstown in Dublin on November 15th 2014.
He, along with six other men including Solidarity Councillors Kieran Mahon and Michael Murphy, has also denied falsely imprisoning her adviser Karen O'Connell during a water charges protest.
The process of selecting a jury to hear what's expected to be a six-week trial is now underway.
The judge has asked potential jurors to consult their consciences if they’ve been active in campaigns for or against water charges.
False imprisonment is one of the most serious criminal offences in Ireland and carries the potential penalty of life imprisonment on conviction.
The prosecution is due to open its case tomorrow.