Bus drivers will be working to rule during the Festival of Motorcycling next week - in a dispute over taking time off during the TT.

Unite regional officer Eric Holmes said the action was aimed at making management ’sit up and take notice’ - and warned it could escalate if it was not resolved.

’The drivers have been on strike before,’ he pointed out.

The current dispute centres on the removal of annual leave during TT.

Mr Holmes said this had been reduced over the years from 15 off at any one time, to 10 and now eight.

The management’s offer was to reduce this to six and for staff to have to book their annual holidays up to nine months in advance.

This went to ballot and was unanimously rejected by the Bus Vannin drivers.

The union has notified the government and the industrial relations office that the drivers will work to rule.

Services will continue to operate but the staff will work to their 42 hours a week contractual obligations and work no overtime.

Mr Holmes said director of public transport Ian Longworth has now told the drivers that all leave during next year’s TT will be cancelled.

The Unite leader said: ’This has never been an issue before. Some of the drivers are marshals.

’This does not mean a strike. Buses will run but the drivers won’t work overtime.

’This should not be a major impact on visitors and anybody else who use the buses. However, this is being done to make management sit up and take notice.

’This could well escalate.’

Bus drivers last took industrial action in 2013 when they went on strike in a long-running dispute over changes to their contracts.

The work to rule begins at just after midnight on Monday morning and runs through to midnight on Friday.In a statement, the DoI said it was disappointed its proposals on bus drivers’ holiday entitlement have been rejected.It said it is working to ensure bus services operate as normal during next week’s industrial action, although some disruption is possible.