The leader of the Catholic Church in Scotland, Cardinal Keith O'Brien, has warned Catholic politicians that if they support abortion, they cannot expect to receive Holy Communion or remain full members of the church.

Cardinal O'Brien delivered a sermon at St Mary's Cathedral in Edinburgh to mark the 40th anniversary of the act which legalised abortion in Britain in 1967.

In what has been described as his boldest intervention yet in political life, he urged Catholic voters to reject politicians who support 'a social evil'.

While the Scottish Executive considers the remarks, Liberal Democrat MSP, Jeremy Purvis, fiercely criticised the cardinal.

However, Michael McMahon of Labour defended the cardinal saying Pope Benedict made the same announcement in Brazil recently and that the cardinal was just reiterating the position of the Catholic Church.