The strikes, over redundancies and a pay freeze, were set to cost the airline £138 million.
Commenting on today's decision in the High Court, TUC general secretary Brendan Barber said: "This is a desperately worrying judgment. A strike that clearly has majority support has been turned over on a tiny technicality. This - and other recent decisions - begins to make it look as if there is no effective right to strike in today's Britain.
"Just as you do not have to agree with what people say to defend their freedom of speech, the right to take peaceful industrial action goes far wider than any particular dispute and is a hallmark of a free society. All fair-minded people should see that fundamental freedoms are now being eroded."
And the news comes as trade union Unite launched an advertising campaign to drum up public support for British Airways staff, labelling the airline ‘Brutish Airways' and carrying the slogan 'BA's bullies are keeping me grounded'.
Commenting on the ruling Andy Cook, chief executive of industrial relations advisers Marshall-James, said, "Unite has once again suffered a defeat at the High Court for not following the correct balloting procedures. This is embarrassing for them and is sure to anger union members who look to their union to represent their best interests. This injunction only means a postponement of any action, but it does mean that momentum will inevitably be lost. These mistakes must be costly for Unite and its members.
"I am sure we will see Unite announce more action as everyone involved in this strike - BA Management, Unite and the Cabin Crew - are showing no signs of compromise. We are seeing brinkmanship at its most extreme.
"It seems utterly amazing that a prestigious British company that touches so many people across the world has ended up in this position. Any negotiation where either or both sides are backed into a corner is a disaster as it means someone will have to lose face in order to make a break through.
"The company realises it is now addressing a history of past management's reluctance to tackle the union and its power. If they give in now, they will be faced with this same situation again in a few years time.
"Both sides need to find a way to build trust so the future of the airline is secured. The travelling public will not endure much more disruption to travel plans."
