The head of the Roman Catholic Church in Scotland has given his backing to independence for Scotland, declaring he would be "happy" if Scots wanted separation.

Cardinal Keith O'Brien, said nations such as Ireland and Denmark benefited from the "prosperity which self-determination can bring".

O'Brien also voiced his frustration with the Scottish Parliament and predicted independence is coming "before too long".

His remarks appear in an interview with the Catholic Herald newspaper and St Andrews University philosopher John Haldane.

Asked if the Church could be indifferent to a move towards independence in Scotland, he declared: "I would not get too involved in the politics of independence, but I am happy that, if it is the wish of the people, Scotland becomes an independent country."

He added: "In my travels I have had much experience of small countries and I have seen what benefits independence can bring.

"There is currently some frustration among the Scots about the say they have over what happens here, and that is part of what is pushing the independence movement. I can see this coming, perhaps not in the next few years, but before too long."

O'Brien concedes that, as the leader of a Scottish Church which is itself independent from England, "it is difficult to argue that ecclesiastical independence is acceptable but political independence is not".

Asked by Scotland on Sunday to expand on his views, O'Brien talked of the advantages other small countries have experienced since getting independence.

He said: "Ireland would be an example of a country which has prospered since achieving independence. Additionally, other northern European countries such as Norway and Denmark exemplify the prosperity which self-determination can bring."

O'Brien also acknowledged the growth of nationalism across the nations of the UK. "I am aware of a growing sense of nationhood and national identity in England, exhibited recently during the World Cup campaign and reflected in the increasing appearance of the St George Cross at such sporting fixtures and other gatherings. In this context, Scottish national identity has always been strong. Ultimately multinational identities are harder to express than national ones."

He also picked out the current debate over the future of Britain's nuclear deterrent. O'Brien recently joined the Moderator of the General Assembly of the Church of Scotland in condemning plans to replace the UK's Trident system as "iniquitous, irrational and absurd".