Lord Steel of Aikwood has criticised Scotland's leading Roman Catholic for likening the abortion rate to the equivalent of "two Dunblane massacres a day".

The Liberal Democrat peer also rejected Cardinal Keith O'Brien's claims that the Abortion Act - which Lord Steel piloted through the House of Commons when he was an MP - was founded on "lies masquerading as truth".

Writing in The Herald today, Lord Steel defends the 1967 act, which he said had prevented the deaths of hundreds of women.

"If termination of pregnancy has to happen it is better to be legal and safe than illegal and dangerous," he said.

Lord Steel was responding for the first time to comments made by Cardinal O'Brien in a sermon he delivered last month.

The cardinal told parishioners at St Mary's Cathedral in Edinburgh: "The abortion industry has impacted massively on the values of our society as its proponents continue to spread their culture of death. There is acceptance of a philosophy, which permits the destruction of children in the haven of their mother's womb."

The cardinal also suggested that Catholic MPs and MSPs who do not work to water down the current abortion legislation may not be entitled to receive Holy Communion.

But it was his Dunblane comments which proved the most controversial.

He said: "We are killing in our country the equivalent of a classroom of kids every single day. Can you imagine that? Two Dunblane massacres a day in our country going on and on. And when is it going to stop?"

Lord Steel said that was an unfortunate remark. "Knowing that the majority does not share his Church's views, he surely would not face the parents of children gunned down in that horror and tell them they had just suffered the same experience as an abortion," he says.

He took "strong exception" to the cardinal's claims that those behind the act had sought to mislead the public when the legislation was in the Commons.

The cardinal said claims that it would end backstreet abortions and that abortions would only be carried out in extreme cases were "a pack of lies and misinformation masquerading as compassion and truth".

But Lord Steel pointed out that his bill was subjected to 18 months of scrutiny and was supported by, among others, the British Medical Association (BMA), the Royal College of Obstetricians and Gynaecologists and the Royal College of Psychiatrists.

Last week, a 10-minute rule was introduced at Westminster by Ann Winterton, a Tory MP, which would compel all women seeking an abortion to receive counselling and information on the potential effects of the procedure, as well as introducing a seven-day "cooling off period".

However, the BMA's annual conference on June 27 will debate a motion proposing further liberalisation of the UK's abortion laws as well as extend them to Northern Ireland.