Reports have suggested that French President Jacques Chriac has visited Saudi Arabia twice in recent months to offer full co-operation from the French on a deal which could see his country's aviation industry cash in on the row between the Saudis and the British authorities.

There has also been a series of meetings in Paris with Prince Bandar bin Sultan bin Abdul Aziz, the Saudi national security council secretary general, last week.

A new French deal could replace a contract for 72 Eurofighter Typhoon jets, built by workers at BAE Systems in Warton and Samlesbury, near Preston, and switch to the French Rafale jet.

It comes as reports from the Middle East kingdom suggest the Saudis have set the UK government a 10-day deadline to intervene into a fraud investigation into dealings between BAE and one of its biggest customers - or it will pull out of the Typhoon deal.

MPs in Lancashire have warned that the jobs of 2,425 workers directly involved with Eurofighter in the county, plus 9,000 others at BAE and thousands more in the local aerospace supply chain, would be at risk should the deal falter.

South Ribble MP David Borrow, a member of the parliamentary defence committee, said: "The Saudis want the Typhoon, they do not want the Rafale.

"This contract includes much more than just jets, it is the weaponary and the long-term maintenance on top of that.

"It is a whole bigger package which builds on what the UK has been doing with Saudi for the last 20 years, so it would be very inconvenient for them to have to switch to a different supplier.

"I would say this is them applying more pressure on the government to intervene into the inquiry, which obviously it cannot."

He reiterated his appeal to the Serious Fraud Office (SFO) to "make some kind of announcement" on its inquiry, which is looking into allegations BAE ran a £60m 'slush fund' to offer sweetners to members of the Saudi Royal family in exchange for lucrative contracts as part of the 20-year Al-Yamamah deal.

BAE today declined to comment on the latest wave of speculation on the contract, which has been going on since comments earlier this week from company chief executive Mike Turner that it was "not progressing" in concluding the deal with the Saudis.

Manufacturing trade union Amicus, which represents workers in Lancashire, has also called on the SFO to reach "a proper and speedy conclusion" in its investigation.

Lead officer Bernie Hamilton said: "It has soured intergovernmental relationships between the UK and Saudi Arabia to the extent that thousands of UK jobs are now at risk."

There are 2,425 people directly involved in Eurofighter at BAE's bases in Lancashire, with 1,875 at Warton and 550 at Samlesbury.

The latest UK-Saudi contract is believed to worth up to £20 billion to BAE, including weaponary systems and long-term maintenance deals.