Protesters predicted Fine Gael will lose seats in the next election because of the party's "dithering" over abortion - and branded the proposed Citizens' Assembly on the issue is "nothing but a whitewash".
The stark warning came as thousands of pro-choice campaigners marched through the streets of Dublin yesterday demanding a repeal of the Eighth Amendment.
Organisers expected an attendance of up to 20,000 - but a combination of poor weather conditions and the Dublin bus strike - affected on numbers.
The demonstration was held as part of a series of similar protests planned for London, Berlin, Paris, and other cities.
A number of pro-choice groups took part in the fifth annual 'March for Choice', organised by the Abortion Rights Campaign (ARC).
Linda Kavanagh of the Abortion Rights Campaign, said the demand for free, safe, legal abortion in Ireland will continue. She accused Taoiseach Enda Kenny and Fine Gael of "ignoring" the voices of women calling for a referendum on the issue.
"I really don't see how a government, even a government as unstable as the current one, can ignore this matter any longer."
She pointed out thousands of women are travelling abroad to avail of abortion facilities in other jurisdictions.
"It is a political mistake to ignore this grassroots movement. They do so at their peril," she warned. Speaking to the Sunday Independent, she argued that up 87pc of the population now want a change to the existing abortion laws.
"The Government needs to understand that this hasn't gone away - we're here to speak for the thousands of women who travel abroad for an abortion every year - and the thousands of women who will travel during the lifetime of this Citizens' Assembly."
Ms Kavanagh described the assembly as a "stalling tactic".
She said "poll after poll" shows that women want the right to choose whether to terminate a pregnancy.
She also said it is important to ensure that women who have had abortions have their voices heard.
The Pro-Life Campaign, meanwhile, held an "awareness event" yesterday calling for the retention of the Eighth Amendment which it says has saved countless lives.
The group produced figures from a special study it commissioned which suggested that, since 1994, some 100,000 lives have been saved because of this amendment.
It stressed that at the heart of the campaign for abortion is a "betrayal both of women and their unborn babies".
Commenting on the findings of the study, Pro-Life Campaign spokesperson, Dr Ruth Cullen, warned of the dangers of "dismantling" the Eighth Amendment.
"Realistically speaking, it is very likely that well in excess of 100,000 people owe their lives to this life-saving provision of our Constitution."
She said pro-choice slogans ignore "fundamental realities" about what legalised abortion actually involves.
There is no choice in abortion for the unborn child, she added, and evidence shows that what is presented as choice for the woman is really "pressure to abort".
"You only have to look at what happens in England - where 90pc of babies diagnosed with Down Syndrome are now aborted. Abortion advocates clearly don't trust women with the truth about their baby and what happens in an abortion," Dr Cullen said.