Last-ditch talks between British Airways and the Unite union were brought to a halt when a dozen or so protesters stormed the Acas building to confront BA Chief Executive Willie Walsh.
According to reports some progress had been made during the talks before the Socialist Workers Party demonstrators interrupted proceedings. The latest strikes follow an ongoing dispute over jobs, working conditions and pay.
Both the union and BA will meet again tomorrow at a secret location to continue the talks.
Earlier Unite's joint leader Tony Woodley urged BA Chief Executive Willie Walsh to change his "petty, vindictive" attitude to secure an agreement and avert 15 days of strikes.
The talks were being mediated by Acas, who have described this weekend as a "window of opportunity". The body said if no resolution is made after this weekend, the whole negotiation process will be problematic going forward.
BA boss Mr Walsh said the union members are "out of touch with reality", but claimed he has made concessions which meant that cabin crew who have taken part in industrial action will not have their travel concessions taken away from them.
If the strikes, which are due to begin on Monday, go ahead - it will cost BA an estimated £100 million. The airline needs to avoid this after posting record losses of £531 million on Friday.