The case of three bricklayers jailed on Friday for refusing to stop picketing a Dublin building site is due back in the High Court today for review.
Family members and supporters say the three men will not purge their contempt.
Keith Kelly (37), Ashlawn Park, Ballybrack; Andrew Clarke (24), Cromlech Fields, Ballybrack; and William McClurg (50) from Sallynoggin were jailed when they said they would continue to picket a Ballybrack site owned by Collen Construction Ltd.
The men claimed they had unsuccessfully sought work at the site.
Collen is building 77 local-authority houses on the site and the construction company began committal proceedings after the men continued picketing despite a High Court injunction restraining them.
Doreen Kelly, a sister of Keith Kelly, said the men would not be purging their contempt.
"We went to see them in prison and it was pretty disturbing for us to see them there," she added.
"We want them out as soon as possible, but they won't be purging their contempt," she said of the three men.
"It is a very important issue, and we've been going door to door, explaining to local people what is going on and asking them to attend the meeting tomorrow night at Ballybrack football club."
A support meeting is to be held tonight at the football club to highlight the case and to plan a protest march on Wednesday afternoon from the Central Bank to a Collen site at Parnell Square in support of the three jailed men, who are members of the Building and Allied Trades Union (Batu).
Socialist Workers Party member Richard Boyd Barrett, of the People Before Profit Alliance, said the men "will not purge their contempt until they get a commitment from Collen for jobs at the site and comply with the Registered Employment Agreement".
He said this was an agreement between the Construction Industry Federation and trade unions that they must employ the appropriate grade of trade union member and for the right pay and conditions.
A spokesman for Collen insisted the company adhered to all industry agreements and that sub-contractors also abided by them. He said there was no dispute between Collen and Batu or Siptu and no case had been made against them.
The spokesman added that there were local people working on the site.
