Britain's best-known labor leader, Bill Morris, says Prime Minister Tony Blair risks losing the next election if he pushes the country to join the single European currency during the current parliament.
Writing in The Times newspaper Tuesday, Mr. Morris said Mr. Blair will be punished by the voters if he concentrates on promoting the euro instead of improving public services.
Mr. Morris also argues that if Britain joins the euro at the wrong time, and for the wrong reasons, it will lead to what he calls "economic meltdown."
The views of Mr. Morris are closely watched in British political circles. He leads the country's third-biggest union, the Transport and General Workers, and he is a close ally of Gordon Brown, the finance minister.
In an interview on British radio, Mr. Morris said voters are not focused on the euro. "It's not the euro that will inform people's decision, I think, at the next election," he said. "It will be the quality of their public services - their health service, transport and education."
He says if Mr. Blair wants to be re-elected as prime minister, he should shelve the euro referendum until after the next election.
"The prime minister should rule out a referendum in this parliament, concentrate on public services, guarantee the third term and then, of course, he can return to the issue," said Mr. Morris.
The current parliament can sit until 2006, when general elections must be held.
Prime Minister Blair has set a deadline of next June for the government to decide whether Britain is ready to join the European single currency.
If five economic tests are passed, Mr. Blair has promised a referendum so voters can choose whether to give up the pound for the euro.