A huge contract which safeguards thousands of Lancashire jobs could be scaled down.
Bosses at the Eurofighter Typhoon consortium, which includes BAE Systems, are looking at the possibility of reducing the third tranche order of 88 aircraft for the UK Ministry of Defence.
It is one of "a number of options" being looked at by the group as cash-strapped UK and Italian government ministers look to find savings in the scheme.
But the manufacturers remain bullish about their position insisting that the consortium has a "legally-binding contract" with the UK and Italian governments, who are looking for the changes.
Eurofighter spokesman Wolf-dietrich Hoeveler said: "The UK and Italian governments asked us to look into certain options and provide them with information regarding these options, which we will do by the end of this year."
Asked whether the options included down-sizing the order, he said: "It does have to do with the numbers of the order."
He added that a memorandum of understanding signed with the governments included conditions which could see them having to pay massive penalty charges as a result of changing the order.
Fylde MP Michael Jack last week quizzed ministers about speculation of a reduction saying it had led to massive "confusion" among BAE's 9,000-strong workforce at Warton and Samlesbury.
Defence minister Derek Twigg confirmed meetings had started, but refused to say if proposals to reduce the total number of Typhoons were under negotiations.
Mr Jack said he is not surprised tranche 3 could now be reduced, confirming his belief that a deal to sell 72 Typhoon to Saudi Arabia could allow a slimming of the third order for the RAF, while at the same time ensuring the overall programme still increases.
He said: "I would not be surprised if they reduce the amount of aircraft in tranche 3 that they would buy for the RAF, bearing in mind that with the sale to Saudi, the overall size of the programme could rise in net terms."