The new leadership of Sinn Fein has been slammed after another scandal over its elected representatives' use of social media.
Senator Maire Devine has been suspended from the party for three months after retweeting a post describing IRA victim Brian Stack as a "sadist prison officer".
Ms Devine went on to argue with Mr Stack's son, Austin, on Twitter.
The punishment handed down by Sinn Fein is the same as that given to Barry McElduff after he posted a video with a loaf of Kingsmill bread on his head.
Relatives of the victims of the 1976 Kingsmill massacre described the tweet as "callous and offensive" and he eventually resigned as an MP.
Last Night, Austin Stack said he wants Ms Devine "to take the honourable action and resign her seat in the Seanad".
He rejected Sinn Fein's apology, saying the reality that Ms Devine will be "welcomed back into the party after 12 short weeks is a clear indication to myself and my family that this has not been treated seriously by Sinn Fein's new leaders".
Mr Stack singled out new leader, Mary Lou McDonald, saying she had announced herself as "new pair of shoes and things would be different".
"Quite clearly that is not the case," he said.
Brian Stack (48) was the chief prison off-icer in Portlaoise prison when he was shot as he left an amateur boxing contest in 1983.
Ms McDonald said yesterday that she has "zero tolerance for people or actions that bring grief to victims or their families".
"Senator Devine understands fully that she made a catastrophic error of judgment in retweeting something that came from a made-up account, I think," she said.
Despite being suspended by the party, a statement was issued on behalf of Ms Devine by the Sinn Fein press office.
In it, she said it was never her intention "to cause any distress or hurt, particularly to victims of the conflict".
"I want to offer my most sincere apologies to the family of the late Brian Stack," she said.