Revealed in Finextra, Cable & Wireless confirmed in a statement that some of its customers, including Citigroup-owned Egg, may be experiencing intermittent, slow or no access to the internet and email services as a result of its network issues.

Customers have been unable to access the banking website since the evening of August 22, 2007. After being down for nearly 24 hours, the Egg website came back online around 5pm on August 23, 2007, This is Money revealed. The publication added that the status of the other affected businesses was unclear.

Although the site was down, customers could still make banking transactions by calling the Egg call center. However, those who did would suffer long queue times, a spokeswoman for Egg admitted, as cited in This is Money.

The online banking group has suffered criticism as a result of the failure. Cited in Finextra, Martin Stern, head of Keynote UK, said: Online-only banks need to ensure their infrastructure performs above-and-beyond their multi-channel competitors and, given the much-lower operating costs of a branch-free model, their margins should be able to fund the building of a world-class online infrastructure.