Arriva and the GWU are holding informal contacts in an eleventh-hour attempt to avert this evening's bus service stoppage, informed sources said this morning.

The GWU has told drivers to stop the bus service from 8 p.m. in protest over what it described as 'long and inhuman' rosters at the bus company. The union has complained that its efforts to resolve the situation in the past four months did not yield results.

Arriva in a statement yesterday said it had done everything agreed with the union so far, and an exercise to further improve the situation was underway.

It is understood that Transport Malta is also involved in the contacts between the union and Arriva.

The Transport Ministry warned yesterday that Arriva is required, according to law, to provide at least a basic bus service, even while there is industrial action.  Bus drivers may be disciplined if they refuse to provide a basic service.