The panel of lawmakers will hear evidence from TSB Chief Executive Paul Pester and the bank's chairman, Richard Meddings, as well as a yet to be named Sabadell executive.

"The Treasury Committee is extremely concerned by the problems at TSB, and by the apparent miscommunication to customers about the extent and nature of these problems," the committee's chair Nicky Morgan said in a statement.

"It's been reported that services such as online banking have been down for some TSB customers for over a week. Many individuals and businesses will have made arrangements for the planned outage, but not for the additional time that the systems have been unavailable."

(Reporting by Huw Jones, editing by Lawrence White)