Workers at Toyota's factories in India did not return to work as scheduled following a week-long lockout, because they refused to sign codes of conduct for their managers, according to union officials.
About 500 staffers gathered outside the twin factories near Bangalore early Monday morning but did not clock in after managers insisted they sign the agreements, according to a local union chief. The units employ some 6,400 people.
Company officials were not immediately available for comment.
Operations were expected to resume after Toyota announced at the end of last week that it had decided to lift the lockout, following a meeting with labour groups which was chaired by a local government mediator.
Unions said at the time that the demand for employees to provide a written undertaking of good conduct before resuming work was "harsh" and also demanded that Toyota Kirloskar Motor reverse a decision to suspend 17 workers.
The Toyota Kirloskar Motor Union has demanded a pay hike of at least 4,000 rupees (£40, €48, $66) a month. But the automaker is offering only 3,050 rupees citing difficult market conditions, with car sales in India down nearly 10% for first time in over a decade.
"As we are against giving or signing any undertaking, none of us has entered the factory for the first shift which began at 6am," Prasanna Kumar, president of the Toyota Kirloskar Motor Employees Union told AFP.
"The undertaking is against our rights as workers. We have a right to protect our interests and ensure that our welfare is not jeopardised," he added.
Earlier, the union had asked the state government "to direct the company to lift the lockout unconditionally" claiming the shutdown was illegal as it was declared without a statutory two-week notice period.
Toyota shut production in India on 16 March, after some workers walked off production lines in protest of a delay in wage hikes, following 10 months of negotiations.
The two factories near Bangalore are Toyota's only vehicle plants in the world's sixth-largest auto market.
Closure would result in a daily production loss of 700 vehicles, Toyota Motor spokesman Naoki Sumino said in Tokyo.