Opening hours will be slashed at four of Merton’s five Tube station ticket offices from this weekend.

London Underground said the cuts made sense as more and more journeys were paid for using Oyster cards and automatic machines – but a charity campaigning for disabled passengers warned it put their safety and independence at risk.

At Wimbledon Park, ticket counter opening hours will fall to less than a third of their current total, and changes will also affect Colliers Wood, Morden and South Wimbledon stations.

Wimbledon Park’s ticket office will only open for two hours a day from Monday to Friday and one hour a day at weekends – currently staff sell tickets for five hours a day during the week, seven hours on Saturdays and six hours on Sundays.

Colliers Wood will close for an extra four hours and 15 minutes every weekday, and South Wimbledon’s Saturday opening times will drop from 13 hours to 75 minutes.

A spokesman for campaign group Transport for All said: “This further excludes disabled and older people from using public transport.

“So many Transport for All’s members rely on staff to help us get around London.”

She said the move would affect people with physical and learning disabilities who found using ticket machines difficult, and threatened to compromise their independence and safety.

A London Underground spokesman said stations would remain staffed while services were running, and the changes reflected customer demand – as passengers increasingly paid for journeys using ticket machines.

Chief operating officer Howard Collins said: “Staff who were previously behind underused ticket office windows will be deployed to places where they can better assist passengers.”

The changes were first announced last year, and will come into force on Sunday.