Politicians should be free to form their own opinion on abortion - even if Church leaders tell them otherwise, Communities Secretary Ruth Kelly says.
Ruth Kelly said abortion was a conscience issue
She told BBC Radio's Today "politicians have to make up their own minds based on their individual conscience".
Cardinal Keith O'Brien said last week that Catholic politicians who defend abortion should not expect to remain full church members.
But Ms Kelly said people held "deep personal convictions on" abortion.
She was responding to Cardinal O'Brien's comments, in which he said pro-abortion MPs should consider their stance on receiving Communion.
"Everybody has to make up their own minds on these issues," she told BBC Radio 4's Today programme.
All three main parties at Westminster say the issue of abortion is one for each MP's conscience, rather than one where there is a party-wide policy.
"We have freedom of conscience issues for extremely good reasons in this country. Issues like abortion and so forth are ones that people have deep personal convictions on," Ms Kelly said.
"Church leaders will always say what they think - that's their prerogative. Politicians have to make up their own minds based on their individual conscience. And that's the way it should be," she added.
Cardinal O'Brien, Scotland's most senior Catholic, in a sermon marking 40 years since the Abortion Act, also called on voters to reject candidates who defend a "social evil".
He was backed by Catholic Archbishop of Cardiff, Peter Smith, who said he would not bar abortion supporters from communion, but advised them not to ask for it.
Meanwhile, Parliament will debate an abortion bill calling for compulsory counselling - rather than the voluntary counselling offered currently - and a seven-day "cooling off" period, to allow women time for further consideration.
It is the third such bill aimed at amending the abortion law since October 2006.