Swimmers at Barnet Council leisure centres will be hit by an increase in prices from June if they do not pay an annual membership fee.

Greenwich Lesiure Limited (GLL), the not-for-profit company which operates the centres on the council's behalf, is introducing a pay and play' membership card, allowing 30 per cent off swimming sessions at their centres - despite session prices remaining the same.

The membership is free until May 31, 2007. After this date, customers living in the borough of Barnet who wish to renew their membership will have to pay £18.50. The fee for those living outside will be £22.50.

At the moment, each session costs £3.50. This price will remain the same for members from June, but non-members would have to pay 30 per cent more - £5.05 per session.

A spokesman for GLL said: "This is a new price which is part of the new pricing structure.

"The new membership has been introduced to offer a huge range of benefits, including access to all leisure centres in the borough and discounted activity prices. GLL always communicates any change in its pricing structure with its customers via clearly displayed posters at the centre and also by receptionists informing customers on entry."

Customer Ian Cohen, of Hillcrest Avenue, Barnet, said: "They did not make it clear you had to join and pay a renewal fee. All they offer is free membership."