Sources close to European Affairs Minister Lucinda Creighton said she is angered by threats that anyone who votes against the Government will see their political careers “destroyed”.
Health Minister James Reilly yesterday denied any bullying had taken place.
Some Fine Gael TDs also expressed frustration, saying their party is being dictated by a Labour agenda.
Ms Creighton said yesterday she wants to remain within Fine Gael but she is opposed to legislating for abortion where a woman threatens to commit suicide.
She also wants an advocate appointed to represent the unborn in abortion cases. Coalition sources say these demands will not be met.
Sources close to Ms Creighton say she is not only preparing to go to the Independent benches but is relieved the final Dáil vote on the Protection of Life During Pregnancy Bill will go ahead this Wednesday.
The TD believes the bill is contrary to what medical experts say and what Fine Gael committed to before the last election, and that politicians should be allowed have a free vote on the bill.
She and colleagues opposing the bill are under pressure from senior Fine Gael figures to support it or face expulsion from the parliamentary party, say party sources close to her.
Four party TDs have already opposed the bill and defied the party whip, but several more could vote against it this week. Party senators could also go overboard after the bill goes to the Seanad on Thursday.
One senior source said: “It’s purely a Labour Party agenda. [Ms Creighton] cannot understand why we’re working against values and best medical practice because Labour is being decimated in the polls.
“It’s so lamentable, being dictated to by Labour. It’s inexcusable. And the tactics being used, the bullying, the threatening.
“Her friends are so destroyed. John Paul Phelan [TD] is one of them. They’re being told they’ll never be elected. [TD] Ray Butler has been told his career will be destroyed too. He’s been told he’ll have to canvass on his own in future.”
Ms Creighton’s husband, Senator Paul Bradford, yesterday warned that Leinster House faced being “enveloped by a [Charles] Haughey fear factor” if pressure forces the bill through.
TDs have also been warned they cannot run for re-election under the party banner.