More than 620,000 Austrians have signed an official petition against a government decision to buy a fleet of new Eurofighter jets.

The tally - more than 10% of the population - means parliament will now have to debate the issue.

The petition was organised by campaigners who say Austria does not need the fleet of 24 planes, being bought from the Eurofighter consortium at a cost of 1.8bn euros ($1.8bn).

But correspondents say the petition is unlikely to derail the plan, which represents one of the country's largest defence contracts since World War II.

We demand an immediate halt to the deal. This is our tax money that is being thrown out the window

Petition organiser Rudolf Fussi

The government decided in July to place the order, seen as a triumph for the Eurofighter consortium which had failed to win any previous export orders.

Officials from the ruling right-wing coalition insisted that the success of the petition would not change their minds, and that the parliamentary debate would not result in a policy reversal.

The success of the petition marks a triumph for its 24-year-old organiser, Rudolf Fussi, who was backed by the Green Party, the Austrian Students' Union and left-wing groups.

"I will make sure that we do not get the war machines into Austria," he said.

"We demand an immediate halt to the deal. This is our tax money that is being thrown out the window."

The campaigners argue that Austria, which is a neutral country, does not need a fleet of high-tech fighters.

They also fear that the costs will mount as the project proceeds - and say the money would be better spent on welfare issues.

Under Austrian law, the population had a week to sign the petition. A minimum of 100,000 signatures were required to force parliament to hold the debate, and even organisers said they were taken aback by the scale of the response.

'Political' deal

But the petition has no power to make parliament block the deal.

The contract is for Typhoon jets produced by the German-based consortium, the European Aeronautic Defence and Space Company.

Austria rejected rival bids from Sweden's Saab, which was offering the Gripen jet, and also the F-16 from the largest US defence manufacturer, Lockheed Martin.

At the time of the decision analysts said they believed the Austrian move was partly political, to bring them closer to Europe's defence structure.