However, the challenger bank revealed that it advanced £1.2bn of new mortgage loans in the first quarter of 2018, building on the £7bn advanced in 2017.

Meanwhile, it also reported that customer deposits grew to £30.6bn, up 3% year-on-year.

TSB has released its results for Q1 2018 amid issues with its new banking platform.

During the weekend of 21-22^nd April, TSB moved its five million customers to the platform but, over the next few days, customers had problems regarding access to accounts via TSB's website and mobile app.

Spanish banking group Sabadell and TSB have appointed IBM to help resolve the performance issues in the platform.

Paul Pester, chief executive officer at TSB, said: “As we moved over to our new banking platform … the landing was an incredibly bumpy one for our customers, and for that I am truly sorry.

“This is not the level of service that we pride ourselves on providing – nor is it what our customers have come to expect from TSB.

“Of course, customers can rest assured that no one will be left out of pocket as a result of these problems.

"We have achieved a tremendous amount in the past four years in building TSB.

“We clearly have some issues we're dealing with, but we will come out the other side.

“The way we deal with every single one of our frustrated customers as quickly as possible will define TSB – both now and in 10, in 15 and in 20 years to come as we continue on our mission to bring more competition to UK banking.”