Labour TD Anne Ferris says she's prepared to be thrown out of the Labour Party for voting in favour of Clare Daly's fatal foetal abnormality bill this evening.

Party leader and Tanaiste Joan Burton believes the bill is unconstitutional.

Anne Ferris was one of 20 Labour members who wrote to former Health Minister James Reilly in 2012 in support of abortion being allowed in the case of fatal foetal abnormality.

She says she would like to see Clare Daly's bill progress to Committee stage so that its provisions can be examined by legal and medical experts.

Speaking on RTE television last night, Deputy Ferris said she's willing to lose the whip on a "matter of principle"