Talks to resolve the dispute at catering firm Gate Gourmet are due to resume even though the company's chairman has left the UK.
The Transport and General Workers union (T&G) and the US-owned firm, which supplies British Airways, will continue attempts to break the deadlock over the 670 Gate Gourmet staff who were sacked two weeks ago.
Chairman David Siegel flew to the US "for a few days" and will return at the weekend. "Informal" talks had continued in his absence on Wednesday, Gate Gourmet said.
The dispute broke out on 10 August when Gate Gourmet sacked the staff after they illegally walked out in protest at the firm's restructuring plans.
British Airways ground staff later walked out in sympathy, forcing the airline to shut down operations at Heathrow airport.
Negotiations between the catering firm and the T&G have stalled over demands that all the sacked workers be reinstated. The union confirmed official talks will resume on this afternoon.