Sir Philip Hampton was in Belfast on Monday to issue a profound apology to customers who have been experiencing problems with their bank accounts since technical glitches hit the lender's IT systems last month.

He said: "Bank systems - bank IT systems - should be amongst the most robust and the most resilient in the world.

"It has taken a lot longer to fix than we thought it might and we do apologise profoundly for that."

He said that fixing the transactions backlog is their number one priority.

"As we go into next week, I think we will have broken the back of the problem if not completely sorted it."

The bank had previously issued assurances as to when the backlog would be cleared - none of which were met.

This should not happen in a bank.

Sir Philip Hampton

"I don't think it would be right to put a precise date on when we can fully remediate everything - but we are making progress every day."

Ulster Bank has said they will ensure that "no one will be left permanently out of pocket" as a result of the crisis.

Initial reviews have indicated that the problem originated during maintenance on systems which are managed and operated by a team in Edinburgh, Scotland - causing an error in their batch scheduler.

As a result, a significant number of customer account balances have not been updating properly since Tuesday 19 June.

The lender said that Ulster Bank payments are sequenced after its sister banks, NatWest and RBS, which led to its backlog being processed after these banks.

"It in no way reflects the priority we attach to our Ulster Bank customers and we regret any confusion this might have caused."

The Northern Ireland Consumer Council has urged management at the bank to establish and execute a plan which will resolve the situation quickly and efficiently for customers.

It is not adequate to tell people on a Saturday that the problem will not be resolved on a Monday as expected.

Antoinette McKeown

"The Consumer Council is aware that paper transactions have been used by tens of thousands of Ulster Bank customers and that all of these transactions will need to be entered into the system. In addition the impact on account holders in other banks could further complicate the resolution of the situation," CEO Antoinette McKeown said.

"End of month pay-day has been and gone, we are in July when many families are taking their annual holiday and will have major concerns about accessing cash abroad."

"It is not adequate to say that customers should be able to visit the limited number of branches that are open later in the evening when this may not suit those who are working full time. Ulster Bank should actively consider early opening hours also - at all branches - to facilitate as many customers as possible."

She said that the bank should guarantee no one's credit rating will be affected and account charges should be waived.

"The Consumer Council has been very disappointed in the lack of engagement by Ulster Bank. There is an opportunity now to be proactive, assist and reassure customers with a clear plan and Ulster Bank need to take that opportunity."

The organisation is demanding that Ulster Bank outline a timeframe within which customers accounts will be resolved; outline how they will expedite the updating and regularisation of accounts and how their customers and others can claim back costs and interest incurred.