The family of Sinn Féin MLA Martina Anderson has launched a stinging attack on the party, accusing them of "publicly humiliating" her.
Ms Anderson and her assembly colleague for the Foyle constituency Karen Mullan last week confirmed they will not stand for the party at the next Stormont Assembly election.
The pair had been asked to step aside following a party review into recent election disappointments in Derry.
In a lengthy post on Facebook by Ms Anderson's sister Sharon Burke on behalf of the wider family, she described it as a "massive miscarriage of justice".
Ms Burke said it was a "brutal way that our loving sister Martina Anderson MLA has been publicly humiliated and asked to stand down by Sinn Féin".
She said asking Ms Anderson to "stand down for problems that were not of her making, is a far cry from the ethos of republicanism".
The post added: "We believe Martina and Karen are being sacrificed by the party, used by this SF leadership because Martina and Karen are the public face and are being castigated in an attempt to win back support.
"Those who thought up that strategy could well see it backfire as the people of Derry do not like to see injustices being inflicted on anyone and as a family we do not believe that using a life long republican as a sacrificial lamb will win back the hearts and minds of republicans in Derry.
"We Andersons believe if Martin McGuinness had been alive he would never have allowed this disgraceful tactic to be deployed. Martina had the privilege of being his junior minister. He knew her well and valued her worth."
It continued: "The British could not do to our Martina what her comrades and friends have done.
"We the Anderson family are crying out for help; we are asking people not to use our appeal as an opportunity to bash SF but to help us correct what we believe is a massive miscarriage of justice.
"We are SF members and as republicans we must demonstrate that we live by our values of equality, respect and integrity – qualities that it pains us to say have been lacking in the treatment of our sister Martina and Karen Mullan."
Ms Mullan was co-opted to the Assembly in 2017 after the post was vacated by Elisha McCallion when she became MP, while Ms Anderson replaced Raymond McCartney in March last year.
Last week, Sinn Féin vice-president Michelle O'Neill said both Ms Anderson and Ms Mullan had "demonstrated great leadership with what was undoubtedly a personally difficult decision".
She tweeted: "Huge thanks to both for their ongoing commitment to the party and to driving change in the Foyle constituency and across Ireland."
