Former British leader Tony Blair has warned of economic chaos should Prime Minister David Cameron's Conservative Party win the May 7 general election.

The ex-Labour leader is set to argue Tuesday that Cameron's efforts to appease the rightwing members of his party and to stamp out a challenge from the U.K. Independence Party is pushing Britain out of the European Union. Blair is warning that such an exit will create job insecurity and "leave a pall of unpredictability hanging over the British economy."

Blair's appearance in his former constituency of Sedgefield will be the first of a series of stops to promote Labour candidate Ed Miliband.

Though Blair won three elections, his legacy is tainted by intervention in Iraq. It is unclear whether voters will be moved by his warnings.