Twitter posts by a Unite union leader have upset negotiations with British Airways (BA) as the two bodies locked horns in a failed bid to prevent strike action.
BA chief executive Willie Walsh has criticised Unite's joint leader Derek Simpson, who sent out numerous tweets updating people on how the talks were progressing.
Walsh told the BBC's Andrew Marr show that he was "shocked and angry" on discovering that Simpson had been busy on Twitter during the discussions.
"Sending out his version of events to the wider audience, that really did undermine my confidence in his desire to resolve this situation," Walsh said.
"It is a really serious issue."
The Tweets may have inspired protestors from the Socialist Workers Party to turn up at the talks, which fell apart this weekend meaning the strikes are set to go ahead again from today.
Walsh is not the only person to be irked by Simpson's actions. A raft of abuse has been posted on the Unite leader's Twitter page and Tony Woodley, the other joint head of the union, has said the tweets were "unfortunate to say the least", according to the Times.
Any serious rift between the two leaders appears to be non-existent, however. Ironically, Unite and Simpson have put out Tweets today indicating a unified front.
"After touring picket lines Tony Woodley and Derek Simpson will address cabin crew at Bedfont FC this afternoon," a Unite Twitter message reads.
Meanwhile, Simpson has Tweeted: "So on with the news ... Tony and I will visit the BA picket lines today ... And if BA are minded we will talk to them."
Simpson is not the first, nor is he likely to be the last, to send out potentially incendiary messages on the micro blogging service. Earlier this year, Labour candidate Kerry McCarthy showed how posting certain information can lead to trouble when she leaked results of her area's postal vote on Twitter.
