The financial services watchdog says tougher lending rules could see a quarter of payday loan firms leave the industry.
The Financial Conduct Authority is taking over regulation of payday loans from the Office of Fair Trading.
The head of the FCA, Martin Wheatley, said: "We've said that up to a quarter could leave, I think the industry itself has estimated figures much higher than that, we'll have to see.
"We'd like firms to rise to our standards but if they can't we'd like them to leave the industry," he told Radio 4's Today programme.
More top news
Star Trek's Captain Kirk said he will not be able to say a final goodbye to Mr Spock because of a charity commitment in Florida.
China's wild Panda population grew by 268 or 16.8% between 2003 and 2013 according to a nationwide survey on the highly endangered mammal.
Approaching Atlantic frontal systems will give a wet and windy night right across the UK with some heavy bursts of rain for everyone.