John Prescott faced a series of revolts over his controversial plans to part-privatise the National Air Traffic Services (Nats) last night with up to 45 MPs rebelling against the Government.
At one point, its majority of 177 was cut to 60, with many abstaining, prompting Opposition calls for the resignation of the Deputy Prime Minister.
While the Government won the votes on rebel amendments to turn Nats into a public corporation or a trust, the size of the rebellion will fuel opposition when the Transport Bill is debated in the House of Lords.
As Labour backbenchers queued up to attack the proposals, Mr Prescott remained adamant that the measure would enhance air safety and bring much-needed investment into the services. He said: "You have to do what is right on safety, that is my obligation and I have always faced that and ifit's not popular, I have to live with it.
"We have heard an awful lot of tosh about the public and the private sector. Do you feel less safe when you are on a private aeroplane? Did you go for British Airways when it was publicly owned?
"I remember King's Cross, I remember Clapham.
"I have never accepted public good and private bad. We have made the arguments and we have made it clear that we can make safety advances."
However, Gwyneth Dunwoody, the chairman of the Transport Select Committee which has been highly critical of the plans, urged MPs: "Do not tonight, I beg you, make the mistake of thinking that a simple company reorganisation will maintain the same standards in the future as we have had in the past.
"I hope that every MP will bear in mind that they will have to live with their consciences on the quality of the votes that they cast tonight."
There were various ways to reform the service, either as a public corporation or as a trust. "The air traffic control services of this country have no comparisons in the private sector. Air traffic controllers do not compete against one another, they co-operate. The men and women working in this sector are absolutely certain that this is not the way forward."
Mr Prescott has repeatedly insisted that safety would not be undermined by the plan to sell off 51 per cent of Nats under a public-private partnership but would ensure that it would get vital capital and expertise from the private sector.
During the debate, Gavin Strang, a former transport minister, said he favoured the idea of setting up a trust that would borrow from the private sector but would be made up of representatives of the airlines, customers, trade unions and all other interested parties. "In my view that is another way of meeting the Government's objectives - if the independent publicly-owned corporation is not acceptable then the trust ought to be acceptable."
Martin Salter, the MP for Reading West, added he was "saddened" to be faced with the prospect of voting against his own party for the first time. "This is nothing short of privatisation and it breaks that bond of trust that we sought with the electorate, the travelling public and the men and women who gave us the finest, most efficient and safest air traffic service in the world."