Payday lenders are failing to live up to the spirit or the letter of codes to which they signed up last year and must do much more to protect vulnerable customers, ministers will warn today.

Short-term loan firms, regulators, charities and Government ministers are being brought together to tackle "deep-rooted" problems across the industry.

Consumer Minister Jo Swinson will warn firms the coalition continues to have serious concerns about payday lending as she launches a review into industry guidelines at the central London summit.

The meeting comes days after the sector was referred for an in-depth investigation by the Competition Commission and will look at whether more can be done to clamp down on bad practice.

Its probe will take up to 18 months and it has powers to ban or limit products and shake up whole markets.

Ms Swinson said: "Evidence of significant widespread problems in the payday market is concerning. Earlier this year we and the regulators announced a strong action plan with immediate and longer-term measures. Today we will be taking stock of progress and looking at what we do next to better protect consumers and address these problems."

The Office of Fair Trading (OFT) referred the £2 billion industry to the Commission last Thursday, citing deep-rooted problems and saying it fears consumers who cannot afford to pay their loans back on time are finding themselves trapped with one firm when their loans are rolled over.

It is also worried firms are emphasising the speed of the loan over cost and that time pressure may encourage lenders to skimp on affordability checks.