British Prime Minister Tony Blair is expected to announce plans today for a referendum on an EU constitution in a reversal that may decide his future and put pressure on other countries for a similar vote.
Mr Blair, who declared only a few months ago he had "no reverse gear", would make a statement to parliament at 12.30 p.m., officials said.
Until now, Mr Blair has said the planned constitution posed no threat to British control of vital policy areas and therefore required no public vote.
British opinion polls show voters are highly wary of closer integration with the European Union. But Mr Blair is apparently betting a promise of a vote - a "No" in any EU state would hold up or possibly even scupper the charter - will take the steam out of the issue.
He is expected to call a general election in about a year, and aides suggested he may be planning to hold the referendum only after being safely elected for a third term.
That would anger the Conservatives, who oppose a European constitution as a threat to Britain's sovereignty and have challenged Mr Blair's Labour government to hold a referendum.