FORMER MEP Patricia McKenna is to dramatically quit the Green Party and run in the forthcoming European elections as an independent.
Ms McKenna said she is leaving the Greens because of its performance in government.
But last night the party rounded on Ms McKenna and claimed her impending departure has been greeted with a sense of relief.
Ms McKenna is to formally make her announcement today.
The independent candidate now faces a bitter turf war with former party colleague Deirdre de Burca.
In the opening round of attacks yesterday, Ms McKenna branded the Greens' ministers, TDs and senators as "nothing but hypocrites". Explaining her decision to exit the party, she said she felt "embarrassed" at the failed promises of the Greens. Ms McKenna also accused its political representatives of "selling out".
Striking back, her former colleague and new constituency rival Ms de Burca criticised the former MEP for announcing her intention to resign in an interview with 'Hot Press' magazine, rather than by talking to the party first. Last night, the party had still not been contacted by Ms McKenna.
Branding her exit as "unsurprising", Ms de Burca claimed there was a "certain amount of relief" following the exit of the party rebel.
Since the Greens entered coalition with Fianna Fail -- a move which Ms McKenna vehemently opposed -- she has offered little beyond "constant criticisms which proved very undermining for her colleagues", Ms de Burca said.
Instead, the former MEP became "addicted to the politics of opposition".
"I'd feel her conduct was very unfair to the rest of the party.
"There are many party members who have gone out and canvassed for Patricia, supported Patricia, given her their time and energy and I feel the least they could have done is to discuss it within the party and let the party know before she announced it publicly."
Since entering Government, Ms McKenna has caused several headaches for the party hierarchy: she contested the leadership against John Gormley, opposed the Lisbon Treaty and called on the party's ministers to resign, withdraw from the Government.
"Patricia has chosen the easy way out. It seems to me she's always on the outside pointing in and criticising.
"It's much harder to be on the inside as the Green Party is now in Government, making change from within," Ms de Burca said.
Last night, as it remained unclear as to when Ms McKenna will officially resign from the party, Ms deBurca hinted that the Greens may simply expel her first.
"It's something we will have to look at," she said. The addition of Ms McKenna to the Dublin constituency ballot sheet makes for four weeks of lively debate amongst her rivals which include the Socialist Party's Joe Higgins, Sinn Fein's Mary Lou McDonald, Libertas' Caroline Simmons, Fianna Fail's Eoin Ryan, Fine Gael's Gay Mitchell and Labour's Proinsias deRossa.
In the 'Hot Press' interview to be published today, Ms McKenna claimed Environment Minister John Gormley has lost all credibility and accused Communications Minister Eamon Ryan of abandoning core Green policies and campaigns.
"I really don't know how Eamon can live with himself after all his promises," she said.
Earlier, party leader John Gormley raised eyebrows when he remarked that Fianna Fail is "not doing too well" when he announced the party's candidates for the two by-elections.