The Christian Socialist Movement has paid tribute to Prime Minister Tony Blair who announced on Thursday that he will step down from office on 27 June after 10 years in power.

Blair announced his departure in a speech to party members in his Sedgefield constituency on Thursay in which he said it was up to other people to decide whether he had mistakes, but said he had always done what he thought was "right".

"I may have been wrong. That's your call.

"But believe one thing if nothing else, I did what I thought was right for our country. And I came into office with high hopes for Britain's future, and, you know, I leave it with even higher hopes for Britain's future.

"Actually I've been lucky and very blessed. And this country is a blessed nation.

"The British are special - the world knows it, in our innermost thoughts we know it. This is the greatest nation on earth," he said.

The Christian Socialist Movement praised Blair for speaking openly about his Christian faith throughout his time as prime minister.

"Tony Blair has made no secret of his Christian faith and its importance to him, and Christian values have clearly informed government policies in the area of the minimum wage, giving pensioners, children and working families a better deal, and tackling global poverty," said the Director of CSM, Andrew Bradstock.

"Even where Mr Blair's actions have drawn criticism from the churches - for example, over Iraq - he has clearly shown himself to be a 'conviction' politician, driven by a concern to do what he believed to be right."

Church leaders have also paid tribute to Blair, particularly his achievements in Northern Ireland, although Iraq has remained a sore point with many.

The Archbishop of Canterbury, Dr Rowan Williams, said, "The Church of England, in common with all people of faith, is grateful that over the past ten years the Prime Minister has refused the demands of some to close down the space in our society within which both vigorous debate and the full diversity of religious conviction can find voice and be expressed."

The Archbishop of York, Dr John Sentamu, said that while he "fundamentally disagreed" with Tony Blair over the invasion of Iraq, he praised Blair for upholding the right to public debate.

"Tony Blair always welcomed what he termed 'prophetic wisdom' from the Church on matters of state, even where such wisdom took the form of criticism or disagreement.

"Such disagreement should not detract from many of the remarkable things Tony Blair has achieved in office, not least among which was the peace settlement in Northern Ireland, where he ensured that past prejudices and failures were not allowed to get in the way of constructive dialogue and peace," he said.

The head of the Roman Catholic Church in England and Wales, Cardinal Cormac Murphy-O'Connor, meanwhile, said, "For my part, I want to recognise and thank Tony Blair for his dedication and whole-hearted commitment to the service of his country.

"In particular, I would warmly commend his efforts in securing peace in Northern Ireland and his constant concern for the eradication of poverty in Africa."

The Moderator of the General Assembly of the Church of Scotland, the Rt Rev Dr Alan McDonald, said Blair's efforts in Northern Ireland should be a particular source of pride: "Tony Blair's achievement in leading the United Kingdom for ten years is remarkable.

"Though the ever-widening gap between rich and poor, the attachment to American foreign policy, and the decision in favour of a new generation of nuclear weapons are all matters of great regret, I would rather concentrate on positives," he said.

"The provision of undreamt of resources for education and the health service, and the speed with which the promise of devolved government was delivered in Scotland and Wales, should be a source of pride for him.

"Above all, history should remember him for the peace process in Northern Ireland."

A chorus of tributes to Blair's successes during his decade in power have poured in from senior political leaders including his likely successor Chancellor Gordon Brown, who praised Blair's "unique achievements" and "unique leadership".

Former Labour leader Lord Kinnock said in an interview with BBC Radio 4's Today programme that, "The one word that has to be associated with Tony is 'winner'.

"Not just of the unprecedented succession of three elections won by the Labour Party with large majorities, but also a winner because of his utter insistence and his endurance in Northern Ireland."

He said, however, that Blair's legacy would be "certainly shadowed, probably in the short term obscured" by the "great tragedy" of the war in Iraq.

Blair, an Anglican, praised the contribution of Christian and other faith groups in society, and often encouraged them to do more, but, always professed that politics and religion should be kept separate.

In 2005, he told a group of evangelical Christians in London, "I do not want to end up with an American-style of politics with us all going out there beating our chest about our faith.

"Politics and religion - it is not that they do not have a lot in common, but if it ends up being used in the political process, I think that is a bit unhealthy."

He remained a firm supporter of faith schools, however, and voiced his firm support on numerous occasions for the continued contribution of Christians in education. And despite his strong will to keep religion out of politics, he remains one of the most publicly Christian Prime Ministers in Britain for more than a hundred years.