The chief executive of Royal Bank of Scotland, the owner of Ulster Bank, will reportedly be hauled in front of a British parliamentary committee to explain its latest IT failure, which last week caused delays in the payments system of all four of its banking units, including Ulster.

Andrew Tyrie, the chair of the UK Treasury select committee, wrote to the group's chief executive Ross McEwan following last week's outage, which saw 600,000 payments fail at banks including Ulster, Natwest, Coutts and RBS.

The Sunday Telegraph reported at the weekend that Mr McEwan could not yet formally be requested to appear in front of the committee, but that it is considering calling him in as a witness.

Mr Tyrie previously wrote to RBS in 2012 seeking answers after a 23-day systems crash left many RBS customers, including its Ulster account holders, unable to properly access their accounts.

The group was fined £56 million by the Bank of England and the UK’s Financial Conduct Authority following the problems of three years ago.

RBS last week apologised to its customers for the latest glitch, saying the issues “have now been resolved and accounts have been updated”. The company has committed to spending a further £150 million per year to restore the effectiveness of its technology systems.