 Broughton is a jewel for the aerospace giant. Yet fears remain we will lose valuable work to our EU partners.  By Karl West agiant grey metal box, bigger than Wembley stadium, perched in the North Wales countryside is the unlikely home of the future of British manufacturing.  Inside airbus's 46,000 square metre factory, huge yellow cranes slide almost silently across the ceiling 23 metres overhead. They carry the large panels that will be pieced together into the complex's prize product - aircraft wings.  about 8,500 piles were driven 20 metres into the ground to support the 8,000 tonnes of steel and concrete that make up the grey box. It is held together with 250,000 bolts and, at last count, 58,000 metres of cable have been installed - enough to stretch all the way from Broughton to Manchester.  It is calm and quiet inside at the moment. This time next year, however, this "factory of the future" will be a hive of industry. at full production it will have 600 workers producing airbus's first all carbon composite wings for the new long-range a350.  These lightweight wings will contribute to what airbus hopes will be an aircraft 25% more efficient than one of its rivals, the american Boeing 777.  as growth is stalling in other parts of the economy, the hightech factory is precisely what George Osborne was referring to when he suggested that a "march of the makers" was needed to drive exports and rebalance the economy.  The aerospace sector is key to this - it supports about 360,000 British jobs and exported more than ?16 billion of equipment last year.  Tom Enders, chief executive of airbus, was clearly chuffed to have David Cameron on hand last week to celebrate the factory opening. "This government wants to underline its support perhaps more strongly than previous governments," Enders said. "His presence here is a message in itself."  Enders is clear as to why airbus, owned by EaDS, the pan-European defence group, keeps bringing the work for its wings to these shores instead of to its other national stakeholders - France, Germany and Spain: because Britain has world-beating know-how in the aerospace sector.  Broughton - which produced the Wellington bomber in the 1940s - and its sister factory at Filton in Bristol, form airbus's centre of excellence in wing design and production.  The two plants are responsible for almost all the wings on the company's planes. allied to this, Enders is acutely aware of the strength of the supplier base in Britain. Rolls-Royce makes some of the best engines, airbus buys landing gear from Messier-Dowty and components from GKN.  Wing production is technical and high-value and is often referred to as the jewel in the airbus crown. This precious gem is coveted by the firm's factories in France, Germany and Spain. and aerospace executives fear that anything less than total commitment from government for future projects could see these factories get their wish, leaving Britain out in the cold.  Enders laughs off the suggestion: "This is a very British thing. You always think others want to take it away, but there is nobody in France and Germany that can do what you do in the UK."  Broughton has produced 14,000 wings over the past 40 years. Enders noted that airbus currently has a backlog of some 4,200 aircraft, including 567 firm orders from 35 customers for the a350.  "all these aircraft will be winged by the UK," he said. "I don't see any reason why the UK won't remain the centre of excellence in wing design and production into the future."  The British paranoia is not completely without foundation, though. The "work share" split, which determines how much work will go to the four countries that form airbus's core stakeholders, seems to suggest that Britain is already losing out. Our share for the a380 was 20%; it is to fall to 15% for the a350.  The work share has previously been linked with the amount of repayable loans that each of the four countries stumps up to help develop aircraft.  For the a350, Britain's aid totals ?340m, while France and Germany pledged a combined (EURO)2.5 billion (?2.2 billion) and Spain (EURO)400m.  airbus executives said that while most of the work remains concentrated in France and Germany, the company will continue to outsource more to low-cost manufacturing countries such as China and India in the future.  The threat of growing expertise in these countries poses a further potential headache for Britain's aerospace sector.  This know-how is a huge benefit, providing 10,000 highly skilled jobs at airbus in the UK - 6,000 at Broughton, and 4,000 at Filton. The company estimates it supports about 100,000 jobs around Britain through its supply base.  another reason for Enders's buoyant mood is the success of the revamped a320, which promises to cut fuel consumption by 15% with its new, cleaner jet engine.  With the price of oil hovering around $100 a barrel for some time, the prospect of making a 15% fuel saving had airline chief's banging down Enders's door for the plane.  The decision to press ahead with the "new engine option" for the short-haul workhorse caught rival Boeing on the hop as it dithered about what to do with its 737.  as a result, the new a320 already has more than 1,000 orders, and it has forced Boeing to finally say it will re-engine the 737 in response. Enders said: "That was a major strategic decision for us, no doubt."  He noted that the singleaisle market is the company's "bread and butter" business, adding: "So to make the right move at the right time was incredibly important. Sometimes you  