They also fear that a privatised version of the National Air Traffic Control System (Nats) will be dangerously powerful, and will aim to take over smaller, privatised systems run by other countries.
Both Britain's EU partners and the European Commission fear the impact of the sale on plans to solve what Brussels has described as the "catastrophic situation" of severe delays and air congestion through the integration of Europe's air space.
As one Brussels source put it: "There is huge anxiety about the UK privatisation across Europe. The European Commission sees integration as the priority to ease congestion and improve safety and thinks Britain going off on its own sell-off is going to hamper those plans."
Many EU states are also putting pressure on Brussels to wade into the row over Nats because they fear that once sold off it would have an unfair commercial advantage and "be powerful enough to take over most of the rest of Europe" through forced takeovers of smaller privatised services.
"They think that a privatised Nats would expand rapidly and gobble up smaller countries' control services such as the Netherlands, Belgium, Italy or wherever," explained Peter Quaintmere, technical director of the International Federation of Airline Pilots Associations.
"It would effectively be a privatised integration of European airspace, not the Government-controlled one that most people want."
Meanwhile at the EU summit in Helsinki Lionel Jospin, the French Prime Minister, reopened the war of words with Britain over beef when he made a strong defence of France's refusal to lift its ban on imports.
At the close of a summit overshadowed by the beef crisis, Mr Jospin insisted that he was defending the interests of "not just of the consumers of France but also European consumers" against a "terrifying and fatal illness which leads to death": CJD - the human equivalent of mad cow disease.
There were, he added, remaining doubts over the transmission of the illness, insisting that Britain needed to "remove those doubts before we lift the embargo". "All the political forces," he added, "from the opposition to the political majority, all the consumers' associations and all the trade unions have approved the position taken by the French government."
French officials even suggested that Paris might prefer to pay punitive damages if it was condemned by the European Court of Justice rather than lift the embargo, given the depth of public anxiety about mad cow disease.
The European Commission will launch its legal action on the beef issue on Tuesday, giving France just five days to reply instead of the normal 60 days.
Mr Blair's aides accused Mr Jospin of "going through the motions" to seek to justify a decision he knew to be wrong, while Mr Blair sought to cool the beef row by declaring that he would not emulate Margaret Thatcher by "handbagging" fellow EU leaders.
"I am not playing the game of a British Prime Minister ending up swaggering around the place, trying to say I have had to handbag everyone to get my way, " said Mr Blair, who called for a more "mature" relationship with Britain's EU partners.
Mr Blair also conceded there was still a "big argument" over EU plans for a savings tax, an issue the summit kicked into touch for six months by setting up a working group.Reuse content