The strikes will be staged October 30, November 1, November 30 and December 2, the civil aviation employees union said in a statement.

The public airline’s violations of their contracts “cause a continuous and systematic degradation of work conditions,” the union said, citing the issues of rest time between flights and the right to take at least one weekend off in seven.

A bid to privatise the airline failed in December 2012, and the government is in the process of deciding whether to try again, after a period of turbulence that has seen a series of technical incidents and a pilots’ strike in August.