The deal for the planes, which are being built by Britain, Germany, Italy and Spain, is said to have secured 14,000 jobs in the British defence industry. That works out at pounds 1m for each job, or pounds 66m for each aircraft.
Labour and the Liberal Democrats locked themselves into the decision, welcoming it as a necessary enhancement of the RAF's defence capability.
The only hint of qualification came from the Liberal Democrat spokesman Menzies Campbell, who confined himself to caution about cost and time over-runs on a project that is already pounds 1.3bn over budget and three years late.
John Weston, chairman of British Aerospace's defence division, said at Farnborough Air Show that the total project would be only 7 per cent over budget. "We think that's not a bad record for a programme of this complexity," he said.
The single-seater Eurofighter made a dramatic debut at the show in front of hundreds of trade and press spectators yesterday.
John Turner, the RAF test pilot, was ecstatic about the aircraft's capabilities. "I have to say you really feel like a king in this," he said. "We want someone to come and attack us so you can really see what this aircraft can do."
The project's official title, "Eurofighter 2000", had become something of a joke in the industry as the delivery date slipped towards 2005.
British Aerospace, however, insisted that many of the complex computer software problems which have dogged the development have now been solved. Managers were "absolutely confident" that the first planes bound for the RAF would be in service in 2001.
Though the UK is now apparently behind full-scale production, the Germans have yet to commit themselves to firm orders. The German parliament is due to vote on the project, which envisages 180 Eurofighters for Germany's air force, by the end of this year.
But Michael Heseltine, the Deputy Prime Minister, who opened the air show and who helped to initiate the project in 1983, was confident that the Germans would give the Eurofighter their full backing.
Mr Portillo said: "Today's announcement is excellent news for the Royal Air Force.
"It represents a crucial step forward towards providing them with a multi- role aircraft with the operational flexibility to respond to the uncertain challenges of the next century.
"The four-nation Eurofighter programme will ensure that the European aerospace industry remains at the forefront of technology."
The Eurofighter will be assembled at British Aerospace sites in Lancashire while Rolls-Royce will manufacture the engines, primarily at Bristol and Derby.
Dr David Clark, shadow secretary of state for defence, said: "For too long ministers have played politics with the jobs of our defence workers. The Eurofighter is vital to meet the future requirements of our armed forces."
While the Liberal Democrats joined the uncritical welcome, Mr Campbell added: "The industrial implications of this project are as significant as the military ones, but the Government must show a higher degree of financial control. Cost over-runs on Eurofighter will only damage the rest of the defence budget."