At-a-glance: Referendum statement http://news.bbc.co.uk/1/hi/uk_politics/3641693.stm
Here are the main points of Tony Blair's statement about holding a referendum on the new European constitution, together with the main party leaders' responses.TONY BLAIR
The prime minister opened his statement by saying that European enlargement was a "historic" step and would transform Europe within a few years.
"I say unhesitatingly that enlargement is right for Britain and for Europe," he said. Mr Blair said the new-shape Europe had to be centred around "sovereign states". That meant keeping the national veto on key issues during the negotiations on the new treaty this summer, he said.
Mr Blair said "myths" about the new constitution had been spread by politicians and parts of the media hostile to the project.
It was wrong, for instance, to suggest that the Queen would be replaced as the head of state. It was already agreed that Britain would keep its right to control its borders, he said, and the British criminal justice system was not at stake.
Mr Blair said there had been an "unrelenting, and I have to admit partially at least, successful campaign to persuade Britain that Europe is a conspiracy aimed at us". Such claims were nonsense and had to be confronted, he argued. Parliament should debate the treaty once it was agreed, "then let the people have the final say", said Mr Blair. The referendum would focus on the new constitution but its implications would go wider. "It is time to resolve whether this country, Britain, wants to be at the centre and heart of European decision making or not," said Mr Blair.
The prime minister said the Tories opposed the constitution in its entirety and wanted Britain reduced to "associate membership" of the European Union. The choice was for Britain either to be at the heart of Europe or to "retreat to the margins", as Tory Eurosceptics wanted, said Mr Blair. Asked if ministers would be able to campaign on either side of the referendum campaign, the prime minister said it was the government's collective position to support the constitution.CONSERVATIVE LEADER MICHAEL HOWARD
The Tory leader welcomed the prime minister's change of heart, saying Mr Blair had "at long last seen sense". Mr Howard read out some of the prime minister's previous statements opposing a referendum on the constitution, saying: "Who will ever trust you again!" The Tory leader demanded to know when the policy had changed and whether the U-turn was down to principle or just opportunism. Mr Howard mocked Labour MPs as being the "loyal foot soldiers of Grand Old Duke of Spin". They had been "marched up to the top of the hill" to oppose a referendum three weeks ago and now were being marched back down again, he said.
Mr Howard appealed for a referendum to be held as soon as possible after EU leaders agreed a constitution deal, rather than waiting for MPs to scrutinise the new treaty. There was "no case whatever" for asking Parliament to spend months on ratifying the treaty before holding a referendum.
He went on: "How can the prime minister say: 'Trust the people, but not just yet?'"
Mr Howard said that if any European Union country rejected the constitution the document would be "dead". Britain would remain in the EU even if it rejected the constitution, said the Tory leader. Mr Howard added: "Let's have the honest debate about Europe that the prime minister says he wants - not a debate about the Aunt Sallies which his statement was full of."
LIB DEM LEADER CHARLES KENNEDY
Mr Kennedy welcomed the referendum decision, whatever its motives. He said the decision was "overdue" but worried that Mr Blair could fit in the vote according to his own general election timetable.
The public wanted unbiased information about Europe, said the Lib Dem leader. "Those of a Eurosceptic or hostile disposition have been allowed far too much of the running," said Mr Kennedy.
He urged the prime minister to re-establish a cross-party, pro-European British campaign group. "Spin" from Downing Street would not help the campaign, he warned. Mr Kennedy pressed for an "unloaded, unbiased question, subject to the Electoral Commission". He described the vote as "an opportunity to at last settle an issue that has bedevilled two generations of politicians."