Senator David Norris has checked himself out of his cancer treatment in hospital to launch an impassioned plea for the Government to abandon plans to abolish the Seanad.
The former presidential candidate and gay and human rights campaigner accused Taoiseach Enda Kenny of trying to rip democracy from the public.
The Senator said Mr Kenny has "blood on his fangs" as plans continue to run a referendum in the autumn.
"This is not turkeys voting for Christmas," he said of Mr Kenny's hopes that senators will support the Seanad's abolition.
"It's turkeys being invited to slit their own throats, eviscerate themselves and stuff themselves at the instigation of the Taoiseach. There isn't even a suggestion of a vegetarian alternative because Mr Kenny from the west of Ireland has blood on his fangs."
Mr Norris made his fiery speech just hours after checking himself out of St Vincent's Hospital in Dublin, where he was being treated for a serious cancer condition.
Mr Norris said he had been discharged to make it on time to the Seanad debate on its potential demise.
He claimed he wanted to reveal the Taoiseach's true colours to the Irish public, claiming that there is no intention for the Government to reform the Dail should the electorate vote to abolish the upper house.
"I reiterate my challenge to Enda Kenny to come into this house - or to better still on TV or radio," Mr Norris said. "I'll debate it with him and I will peel the layers of dishonesty and populism away from him and show the Irish people what is really being done to them so they won't be fooled another time until they know which way to vote."
The Taoiseach unveiled details of the referendum on the scrapping of the Seanad earlier this month. He said radical change and reform was needed to bring Ireland into the 21st century, describing the upper house as outmoded and elitist.