Catholic schools fuel sectarianism and should be phased out, said Lord Steel as he intervened in the row over denominational education in Scotland.
The Liberal Democrat peer and former presiding officer of the Scottish parliament said there was "stark evidence" that separate schools for Catholics and Protestants were perpetuating the religious divide.
Writing in The Sunday Times, Steel accused the Catholic Church of "burying its head in the sand" by refusing to acknowledge that faith schools were divisive.
While Steel welcomed religious and moral education, he said it was most effective in a non-denominational setting.
His intervention has drawn an angry response from the Catholic Church, which has insisted that the future of Catholic schools is not a matter of pressing public concern and that to debate the issue risks "fanning the flames of religious hatred".
Cardinal Keith O'Brien, the head of Scotland's Catholics, has accused the media of anti-Catholic bias in its coverage of denominational education and is to launch a "media monitoring" campaign in the New Year.
In other news, leaders of the Church of Scotland and the Catholic Church in Scotland are to issue a joint New Year message for the first time, as they attacked sectarianism and the proposed replacement of Trident.
Cardinal Keith O'Brien and the Rt Rev Alan McDonald, Moderator of the General Assembly of the Kirk, will call on MPs to oppose a new British nuclear deterrent, saying they are ashamed of Scotland's "inheritance of sectarianism and violence".
