Workers at the state-owned passenger firm ZUPCO are said to be angry following a decision by their employer to defer paying them their already delayed salaries.
ZUPCO employees who spoke to a local weekly said their bosses had deferred paying them salaries indefinitely for the months of April, May and June.
This is in addition to outstanding 2010 salaries totalling $520,000 the company owes its workers, the Zim Independent newspaper reported Friday.
The workers have also been hit with other unpopular measures, including being forced on to a two-week working month, effectively slashing their wages by half.
Food allowances for all bus crews have been stopped, while the company's contributions towards the workers' pensions have ceased.
Management's attempts to treat maternity leave as unpaid leave was abandoned following strong resistance from workers and their representatives.
Transport and General Workers Union of Zimbabwe general secretary Tafadzwa Matanhiretold SW Radio Africa that even after reducing the workers' hours, ZUPCO was still failing to pay them.
"The workers are getting a raw deal and this is causing them a lot of stress. This is not good for the workers and it is not good for the passengers who have to be transported by a stressed driver.
"Drivers can't concentrate on the roads because they are almost always preoccupied with the issue of their unpaid wages and this puts the lives of passengers at risk. Worse still, most of them do not receive any night allowances anymore," Matanhire said.
In April this year the state-run Sunday News newspaper revealed how ZUPCO buses had been running without passenger insurance since October 2013.
The workers' representative said ZUPCO was always changing its managers and this had contributed to the problems at the parastatal. He said the constant movement at the top bred unaccountability and discontinuity, and affect the company's performance.
Matanhire said in some cases the National Employment Council's retrenchment board was to blame for sitting on cases and evidence that would help retrenched workers get their packages.
As is the case with all Zim parastatals, ZUPCO is in the red and owes creditors at least $20 million. Last year the High Court Sheriff in Bulawayo attached 31 buses after the company failed to pay 67 retrenched workers their exit packages.
The recent 'Salary-gate' scandal also revealed how parastatal executives have been paying themselves fat salaries while neglecting service delivery and staff welfare.
ZUPCO has been recapitalising since 2011 and now has more than 300 buses. Recently legislators learned that ZUPCO also had in its fleet about 50 buses that are unsuitable for the local roads.
ZUPCO ex-chief Brian Chawasarira last year suggested that the company was doing well in its turnaround process due to "shrewd financial resources management and austerity measures".
Aggrieved workers say their welfare has been sacrificed in the process.