John Smith 1938-1994: 'A tough fighter for what he believed in': Widespread mourning for man of dignity and integrity

The Queen, who was informed almost immediately of Mr Smith's death, sent a message of sympathy to his widow while a White House official said President Bill Clinton 'was saddened to learn of the sudden and untimely death of John Smith'. The two men had been planning to meet in June during the President's trip to the United Kingdom.

Baroness Thatcher said: 'He had come into the job of leader of the Opposition, fitting it perfectly. His dignity, his mind and his sense of humour made him ideal for the task.'

Lord Healey, a former Labour chancellor of the exchequer, said he saw Mr Smith as a possible future leader from the minute he went into Parliament. 'He had an extremely hostile press and he triumphed over the whole lot.'

The Archbishop of Canterbury, Dr George Carey, said Mr Smith was passionately committed to the 'possibility of building a society that was both prosperous and just'. He was a Christian man whose faith underpinned his character and vision.

Sir Edward Heath added: 'He was a man of great integrity and experience who throughout his political life in the House of Commons had always supported European unity. He will be greatly missed.'

John Prescott, Labour's employment spokesman, said: 'There is a tear in the eye but a smile on the lips because he had great humour. The priority is to get on with what John would have wanted us to do and that is to fight the Euro-elections. Whilst he won't be with us he will be with us in our hearts and our spirits.'

Tony Blair, shadow Home Secretary, said: 'It is simply heart-rending, devastating for all who knew him and our prayers and sympathy go out to his family. He was a close personal friend and colleague and a leader of extraordinary strength and authority who would have been a great, great prime minister. He will be mourned not just amongst his family, friends and party but throughout the whole of the nation.'

Bryan Gould, who fought Mr Smith for the Labour leadership in 1992, said: 'His death leaves a huge hole in the Labour Party. He was destined to become prime minister.'

The Labour MP Ken Livingstone said: 'Arguments never became personal. He would have been Labour's greatest prime minister since Attlee.'

The television presenter Melvyn Bragg, a Labour supporter, said Mr Smith would have made a 'great and inspiring prime minister. He would have reinstituted public morality - he was the personification of decency itself and he would have expected higher standards from everyone.'

Sir Norman Fowler, Tory party chairman, said: 'He was always an honourable opponent and respected throughout politics. His contribution will be much missed.'

Ian Lang, Secretary of State for Scotland, said: 'I regarded him as a fine parliamentarian, a fair, decent and a good man and a great patriot who loved Scotland and loved democracy.'

Margaret Ewing, of the Scottish National Party, said: 'He was always a respected and honest opponent. His loss to Scotland and to UK politics will be immense.'

The President of the European Commission, Jacques Delors, said he would be 'sorely missed, in particular by all true Europeans'. In a letter to Mr Smith's widow, he wrote: 'Even when the going was difficult, John Smith remained constant in his political commitments to the cause of a modern and generous Europe.'

Willy Claes, President of the Party of European Socialists, said: 'We have lost not just a good friend but a convinced, and convincing European.'

The head of the French Socialist Party, Michel Rocard, who spent Wednesday evening with Mr Smith and his wife, said that the Labour leader had been 'in great shape and his death came as a shock for me'. The Taoiseach, Albert Reynolds, praised Mr Smith's principled approach in resisting the temptation to exploit Irish problems for party advantage. 'He was a man of outstanding ability and stature who contributed greatly to the politics of these islands, particularly in his far-sighted support for the peace process,' he said.

Gerry Adams, the Sinn Fein president, offered 'sincerest condolences' on Mr Smith's death.

The singer Billy Bragg, a Labour supporter, said Mr Smith's death was tragic and it was 'a particular tragedy that he was taken away just as the party was starting to build its momentum after the success of the local council elections'.

Bill Morris, general secretary of the Transport and General Workers Union, said: 'His tragic death takes from us all in the labour movement a great leader and a good friend.'

The Chief Rabbi, Dr Jonathan Sacks, said: 'He was a man of high principle, decency and religious faith. Britain mourns not only a political leader but a fine and moral man.'