METROLINK bosses have been left red-faced after two managers were recorded discussing vital staffing issues on a tram.

The two employees expressed concern about an apparent lack of drivers and predicted that, if some did not work their rest days, the system would "grind to a halt".

Union leaders criticised the pair for talking about the issue in public which highlighted concerns about safety and working conditions.

The Workers of England Union (WOE), which is not the recognised union for Metrolink workers but represents some of its staff, has formally complained to Transport for Greater Manchester about the video, recorded on a tram near Manchester Piccadilly on July 22.

In the video, the pair discuss Metrolink's practise of paying drivers to work on their rest days, rather than employing more drivers.

One said: "Relying on overtime and rest-day working — it’s not a sensible way to operate a network, is it?

"Particularly if there's an industrial dispute and the drivers say 'right, we're going to work to rule and we're withdrawing rest-day working, overtime working', the system would grind to a halt."

He goes onto suggest there will potentially problem if things do not improve by the start of the football season.

Stephen Morris, of WOE's Northern branch, said: "Metrolink added new lines but did not hire enough new drivers so drivers have to work on rest days for the system to run.

"Overworked drivers could lose their attentiveness, which is unsafe.

"According to the staff in this video, all that would be needed for the system to grind to a halt is for drivers not work rest days. It is a concern."

WOE president Eddie Bone said: "The first Premier League match of the season is on Saturday.

"Just imagine the mayhem if Metrolink drivers worked to rule. According to those Metrolink managers it would bring the 'system to a halt'."

A Metrolink spokesman said: "We've been made aware of the video recording of two of our managers and we're currently looking into this matter internally."