A glitch affecting the Northern Ireland-built 'Boris buses' that were supposed to be a cool new addition to London's streets has now been fixed, it has been claimed.
The assurance comes after the state-of-the-art Routemaster buses left passengers fuming due to faulty air conditioning that caused temperatures on board to soar.
Transport for London (TfL) said engineers had worked around the clock to solve the problem, after upper-deck heat levels were recorded at more than 30C.
However, yesterday commuters were still complaining that the top deck of the bus, made by Wrightbus in Ballymena, was still unbearable.
TfL confirmed that a number of buses had technical issues associated with their ventilation, but that these had now been resolved.
Mike Weston, operations director for London Buses, apologised to customers: "Our suppliers have worked throughout the weekend to fix this issue meaning passengers should now be finding temperature levels more comfortable," he said.
Twenty-seven of the buses, championed by London Mayor Boris Johnson, were recently delivered by Wrightbus.
The Ballymena manufacturer is contracted to build 608 double-deckers for London Transport by 2016 at a cost of £212m.