A proposed merger of TUIfly with part of Air Berlin prompted a wildcat walk out in Germany on Friday over fears of job losses.
TUIfly was forced to cancel all but 10 of 108 flights leaving 10,000 people stranded as staff called in sick in protest at the plans.
The Times reported that the government of Lower Saxony tried to intervene to mediate between trade unions and management at TUIfly.
The Air Berlin merger has been proposed to save Germany’s second-largest carrier from insolvency.