Barclays rolled out a new mobile banking feature on Tuesday that allows users to switch off categories of spending including drinking, eating out and gambling.

Customers can access the feature using a smartphone app. If they try to purchase restricted items, the payment will be declined.

The bank said it designed the feature with mental health advisers to help vulnerable people manage their finances. It said beneficiaries might include people who struggle with addiction or mental health issues.

Barclays (BCS) is the first major UK bank to offer the tool. Some smaller online account providers, which are trying to steal market share from big lenders, already offer similar features.

The Money and Mental Health Policy Institute helped Barclays to identify problematic spending categories. The group's founder, Martin Lewis, said the new feature help prevent compulsive spending by adding "friction."

"Making something more difficult to do slows people down, and gives time to consider," he said. "This is important when you're dealing with impulse control."

Barclays will allow customers to switch off spending in five categories: groceries and supermarkets; restaurants, takeaways, pubs and bars; gas and diesel; gambling; and purchases made via premium-rate phone lines.

More than 8 million people in the United Kingdom suffer with "problem debt," which means they are unlikely to repay. One big factor is gambling, which can be done online or in physical stores.

"There are no limits to stakes and prizes for online gambling, and credit cards are allowed so it is important to make it easier for people to control their spending," said Marc Etches, chief executive of the charity GambleAware.

Some card providers offer UK customers the ability to block different kinds of spending, for example online purchases or taking money out of an ATM. However, those features are primarily seen as fraud prevention tools.