A special adviser to former tánaiste Joan Burton has denied exaggerating her evidence when she said she was petrified while delayed in a car by water charge protesters.

Karen O'Connell was giving evidence in the trial of Solidarity TD Paul Murphy and six other men who are charged with falsely imprisoning her during a protest in 2014.

All seven defendants have pleaded not guilty to falsely imprisoning Ms Burton and Ms O'Connell in Jobstown in Dublin on 15 November 2014.

The prosecution says she and Labour TD Joan Burton were trapped in cars for up to three hours.

On her second day in the witness box, Ms O'Connell did not accept that video footage from within the car showed the atmosphere to be relaxed and at times jovial.

Defence Counsel Padraig Dwyer suggested she was exaggerating when describing how she was petrified.

She accepted she could be heard laughing in the car at one point.

She said she believed laughing was a human reaction to a very stressful situation.

She said the defence counsel had played video recordings of just a few minutes of a three-and-a-half hour ordeal and it did not reflect the atmosphere throughout.

"The video clip ... you played is of a certain point on a timeline. When I got into the car at first I was panicked, upset and crying, there were people on all sides of the car taking videos of us," she said.

She said it was a very stressful situation and it was human to laugh with nervous tension.

Ms O'Connell can also be heard saying "this is always the way at the end of a protest, the f***ing dregs decide not to finish it".

Mr Dwyer asked her if as a Labour Party activist for many years, she believed the party was supposed to represent the workers, the poor, the uneducated, the under privileged.

Ms O'Connell said if he was insinuating that she had insulted people, the word "dregs" means the end of something and she believed that an agreement had been reached to end the protest and allow the car to move but some were still blocking its path.

But she said she was embarrassed and not proud of the language she had used adding: "While the language is awful, we had been in the car for three-and-a-half hours at that point...I was upset and I'm not proud of what I said, it is only human when in a situation like that, there is not a person in this courtroom who would not use language in a stressful situation."

Ms O'Connell was also questioned at length about her involvement in the Shell to Sea campaign which Mr Dwyer said involved blockades and sit-down protests.

She repeatedly said she believed there was a significant difference between the actions of the Shell to Sea protesters and what happened in Jobstown.

Mr Dwyer said trucks had been blocked from entering a refinery and cars had been stopped from entering petrol stations.

Ms O'Connell said "no one was ever deprived of their liberty. There is a difference between holding people in place for a long time and preventing people from going up a road".

She said the trucks in Rossport could have left the area, but she could not leave Jobstown.

Mr Dwyer suggested that "in terms of a sit-down protest it does not matter a whit whether you are preventing someone going from A to B or B to A, it is an interference with their right to move?"

He asked if she agreed that the whole point of a sit-down protest was to cause inconvenience, loss or pain.

Ms O’Connell said she believed in peaceful protest to cause an inconvenience but not to the point of distress.

Her cross-examination continues on Monday.

The defendants are: Solidarity TD, Paul Murphy, 34, from Kingswood Heights, Tallaght; Councillor Michael Murphy, 53, from Whitechurch Way, Ballyboden in Dublin; Councillor Kieran Mahon, 39, from Bolbrook Grove, Tallaght; Scott Masterson, 34, from Carrigmore Drive, Tallaght; Frank Donaghy, 71, from Alpine Rise, Tallaght; Michael Banks, 46, Brookview Green, Tallaght; and Ken Purcell, 50, from Kiltalown Green, also in Tallaght.