Tusa is not increasing its variable mortgage rates following the increase in the European Central Bank rate recently. The in-store banking service, launched last autumn by TSB Bank and Superquinn, will hold the current 3.8 per cent APR until at least June 30th. Tusa claims that the rate, based on a £50,000 mortgage over 20 years, is the lowest in the marketplace.

"Our policy is to encourage customers to focus on the lifetime cost of borrowing to buy a home and the APR is the only measure that reflects the true cost of a mortgage," said chief executive, Mr Brian Mahoney.

Tusa's cost base is significantly lower than other financial institutions because many of the transactions are electronic allowing the bank to pass cost savings on to customers. The rates are available to all new and existing customers. Customers can also split their mortgage between fixed and variable rates for maximum protection against interest-rate movements.

According to Tusa the convenience factor - open 59 hours a week, which is nearly twice as long as conventional banks - is the key selling point with the public. The six-function card which includes ATM, Laser, cheque guarantee, SuperClub, telephone banking registration and Eircom charge-card functions has proven very popular with customers. This card was the first of its kind in the Republic. New Tusa outlets are opening in Superquinn stores at Sundrive Road, Carlow and Kilkenny in April.