A leading rail union has attacked the “disgusting and obscene” spectacle of transport managers celebrating the closure of London Underground ticket offices.

The Rail, Maritime and Transport (RMT) union said nearly 50 senior managers attended a black-tie dinner at a Mayfair club to mark the completion of the closure of hundreds of ticket offices.

The union said a “gloating” bulletin circulated to staff said: “Almost 50 people from the FftFS [Fit for the Future Stations] team spent an enjoyable evening in the luxurious setting of the RAF Club in Piccadilly as they celebrated the successful completion of the main ticket office closure programme.

“All 289 ticket offices were closed, within budget, in an immense team effort throughout 2015.”

RMT general secretary Mick Cash said: “It is, frankly, obscene that nearly 50 senior TfL managers treated themselves to a slap-up beano at the luxury RAF Club in the heart of the West End to celebrate the axing of 800 safety-critical jobs and the smashing up of London’s tube ticket offices.

“While TfL is talking about further cuts of over two billion that would devastate safety and services, it is a massive kick in the teeth for staff to receive bulletins from the management gloating about their axe-swinging antics.

“RMT members are furious that while they are being stretched to breaking point, the top brass are out on a jolly in a luxury, private members’ club in Mayfair.”

A TfL spokesman said: “No public money was spent on the dinner organised by some of our construction workers to mark the completion of their building work. The dinner was held in their own time and entirely at their own expense.

“In keeping with his manifesto commitment, the new mayor [Sadiq Khan] is committed to examining the impact of ticket office closures. That review will assess the impact of ticket office closures to make sure that passengers are still receiving the best possible service.”