LONDON - British Prime Minister David Cameron's plan to hold a European Union membership referendum if he is re-elected next month would lead to an intense period of uncertainty for businesses, former British Prime Minister Tony Blair will say on Tuesday.
Cameron, whose Conservatives are neck-and-neck with the opposition Labor Party in most polls ahead of the May 7 vote, has promised to renegotiate Britain's ties with Brussels ahead of a referendum by the end of 2017.
In a campaign speech on Tuesday, former Labor leader Blair, who served as prime minister from 1997-2007, will say the "short-term" pain of Cameron's proposed re-negotiation has been underestimated.
"Think of the chaos produced by the possibility never mind the reality of Britain quitting Europe," Blair, 61, will say, according to extracts released in advance by the Labor Party.
"Jobs that are secure suddenly insecure; investment decisions postponed or canceled; a pall of unpredictability hanging over the British economy," he will say.
If Britain voted to leave the European Union, business would face the most intense uncertainty since World War Two, Blair will say.
"There would be significant business uncertainty in the run-up to a vote but should the vote go the way of exit, then there would be the most intense period of business anxiety, reconsideration of options and instability since the war."
Blair will argue that Cameron made the referendum pledge to appease Eurosceptic members of his party and to try to win back voters who have defected to the anti-EU UK Independence Party.
"This issue, touching as it does the country's future, is too important to be traded like this," Blair will say.
Blair will praise opposition Labor leader Ed Miliband for resisting pressure to promise a referendum.