Public transport drivers from Plovdiv, Varna and Bourgas will join the Sofia public transport protest.

The main demand of the drivers is for a salary increase, Novinar daily reported.

Trade unions said that low salaries caused high staff turnover and a public transport staff shortage.

Drivers currently worked overtime, which damaged their health, Confederation of Independent Trade Unions in Bulgaria (CITUB) said.

The old technical equipment of public transport led to higher costs, which in turn pushed up ticket prices.

On May 9, Bulgaria’s Parliament approved changes to the ordinance regulating salaries of public transport officials of companies with more than 50 per cent state ownership.

The changes envision easing the system of increasing salaries in loss making companies.

Strike committees of public transport employees announced on May 9 that they were not going to postpone the strike which was scheduled for May 15.

The strike will carry on until the demands of the drivers have been met.