The owner of one of the UK's largest banks said the threat of cyberattacks "keep me awake at night".

Ian Stuart, CEO of HSBC UK, said cybersecurity is the “agenda” of its banking group and dealing with IT vulnerability is a “huge” expense for the entire industry.

"It really worries me - we could be attacked, we're always under attack," he said.

Mr Stewart and other bank owners have been talking to the House of Commons Finance Committee, which has been demonstrating a range of issues affecting the industry, including how vulnerable it is in terms of power outages and cyberattacks.

In March, it has emerged over the past two years with nine major banks and a society operating in the UK, accumulating at least 803 hours (equivalent to 33 days).

In recent weeks, retailers’ co-operatives, Marks and Spencer, have suffered severe damage after being hacked.

Lisa Forte of cybersecurity company Red Goat told BBC News that Mr Stuart made a "very important point".

"The number and severity of cyber attacks are increasing," she said.

“Criminals are monetizing attacks more effectively, and we are now in situations where businesses will encounter attacks, which is largely the point.”

Mr Stewart said his banking group is spending hundreds of millions of pounds to improve its IT systems.

“I think the amount of banks (all of us) going to be put into our system is huge,” he said.

“The defense mechanism you provide is absolutely crucial.”

In his group, he said they are processing 1,000 models per second while making 8,000 changes and updates per week.

Barclays, Lloyds, National, Santander, Natwest, Danske Bank, Bank of Ireland and Allied Irish Bank also provided information to the committee.

Between January 2023 and February this year, they experienced 158 failures.

Barclays CEO Vim Maru addressed members of Congress, introducing the Barclays power outage that occurred on January payday.

A report found that serious IT issues affected days of online banking, keeping some from going home - potentially causing banks to face compensation payments of £12.5 million.

Mr. Malu apologized to the customer, saying he was very sorry for the destruction. He said there is no evidence that this was causing a cyber incident or malicious behavior.

After the Barclays incident in January, about 1.2 million people in the UK suffered further power outages in February.

These problems occur at Lloyds, TSB, National and HSBC.