TESCO'S online banking network has been hit by a computer fault, understood to have impacted up to 300,000 customers and their accounts.

 

Tesco Bank said people trying to use current accounts, savings and loans - but not credit card services - had been affected since Tuesday.

The Edinburgh-based bank estimated the glitch was affecting around one in 20 of its customers but Tesco said it had not received "a huge number of calls". The bank celebrated the opening of its seven millionth account last year.

"We are working hard to resolve this matter and that's our focus," it said.

In June, 2011, chief executive Benny Higgins apologised after it emerged some Tesco Bank customers were still locked out of their online accounts a week after the bank moved 850,000 accounts to a new computer system.

Mr Higgins apologised "unreservedly", but admitted that 2,500 customers could not access their accounts.

The problems began after Tesco Bank migrated all its online savings accounts from the Royal Bank of Scotland system to its own computers.

Tesco say the latest network outrage is not connected to their earlier problems, has apologised for the latest inconvenience and thanked customers for their patience.

One customer said that she had been unable to access her account for two days.

"I called Tesco Bank and they said they do not know what the reason for the failure is, and they do not know when this will be fixed," she said.

"The public deserves better information..."

Tesco Bank said it had alerted customers on its website that there was a problem.

However, a spokesman said customers could contact its call centres to process any account services while the problems continued.

The bank said: "We are aware that some of our customers are currently unable to view their accounts in online banking. We are working hard to resolve this matter as soon as possible.

"Customers can still continue to use their accounts as normal and can contact us by phone if they need any help with their account. We apologise for the inconvenience and thank customers for their patience"

In April, last year, Tesco Bank was stung by a £43 million charge to refund interest and charges to 200,000 credit card customers who received late or inaccurate statements over the last five years.

The bank now employs 4000 people including 2000 in Glasgow and 1300 in Edinburgh. The remainder are in Newcastle.

Last year it emerged that in the previous six years, Tesco Bank's deposits have grown by 58% and customer lending increased by 64%.