* Ship is first of pair but prospect for second unclear
* Also unsure how many F-35 fighter jets it will carry
* Scottish touch to ceremony before Sept. referendum
By Sarah Young and Kylie MacLellan
LONDON, July 4 (Reuters) - Queen Elizabeth will officially name the biggest warship Britain has ever built on Friday, the latest step in a 6.2 billion pound ($10.6 billion) project to build a new generation of aircraft carriers.
But the stage-managed show of military might and engineering expertise comes at a time of financial uncertainty and it remains unclear if the vessel, HMS Queen Elizabeth, will be the only carrier of its kind to be deployed by the Royal Navy.
How many U.S.-built F-35 jets it will carry is an open question too for the project 2.6 billion pounds ($4.42 billion) over the original budget set out seven years ago.
For Britain’s naval commanders, it’s a moment to savour and to lobby for greater and continued spending as politicians eye further cuts to the country’s defence spending to help try to reduce large public debts.
“Credibility ... means investment in ships, submarines and aircraft that are capable of credible standards of war-fighting,” Admiral Sir George Zambellas, First Sea Lord and Chief of the Naval Staff, said ahead of the ceremony.
“Because, to put it bluntly, in our line of business, there are no prizes for coming second.”
The event, which will see a crowd of 4,000 gather at a Scottish shipyard to watch the queen smash a bottle of Scotch whisky against the hull, is heavy with political significance.
Scotland will vote on whether to break away from the United Kingdom on Sept. 18 and the campaign against independence hopes the event will remind Scots how many Scottish jobs are underpinned by Britain’s defence sector.
The sector employs more than 12,600 people in Scotland, according to the British government, with around 4,000 jobs directly linked to the aircraft carriers project.
Prime Minister David Cameron, who is campaigning for Scotland to remain part of Britain, will attend. On the eve of the ceremony, he told Scots they’d be safer if they voted “no”.
Even though it has made cuts, Britain remains the world’s fourth biggest military spender and Cameron, the leader of the Conservative party, says an independent Scotland would struggle to match Britain’s armed forces.
Scottish nationalists dismiss that, saying they don’t want Britain’s nuclear weapons on Scottish soil and wouldn’t need such a powerful military anyway.
Britain has cut defence spending by around 8 percent over the last four years as part of a government plan to reduce a record budget deficit, leaving it with an army which by 2020 will be the smallest it has been since the Napoleonic Wars of the early nineteenth century.
The Royal Navy has been hard hit.
It had 50,500 personnel in 1995 but now has only 33,350. The fleet size has also shrunk. In 2005, it had 11 destroyers, 20 frigates and 11 tactical submarines. Today, it has only six destroyers, 13 frigates and seven tactical submarines.
HMS Queen Elizabeth is meant to be the first of two aircraft carriers. But the fate of the second ship is unclear.
Identical to the first, it is already being built, but the government won’t decide whether Britain will use it until a defence spending review in the second half of next year. Defence experts say it could still be mothballed or sold.
Nor has Britain yet ordered the fighter jets for the carriers. The original plan was to buy 138, but so far the government has only committed to 48 and has bought just three for training purposes.
A $5 billion order for 14 Lockheed Martin F-35 super-stealth jets is expected this year however.
While Britain was one of only four NATO partners to meet their agreed target of spending 2 percent of GDP on defence last year, both U.S. and British military officials have said spending cuts could affect its ability to fight wars.
With a deck the size of three football pitches and a belly that can fit a mix of about 40 jets or helicopters inside, HMS Queen Elizabeth is meant to be a gamechanger.
“In terms of size, scale and ability to deliver increased strategic effect and international influence, the two aircraft carriers under construction for the Royal Navy represent a step change in military capability,” independent defence analyst Howard Wheeldon said.
Analysts say the $10.6 billion bill for the pair built by the Aircraft Carrier Alliance - a consortium including British engineering companies BAE Systems and Babcock, and the UK division of France’s Thales - is good value in comparison to the U.S., which spent an estimated $12.9 billion on its new carrier.
The decision about the second ship, HMS Prince of Wales, will be made by a new government elected in a vote in May 2015.
Britain’s economy is improving but the defence budget is likely to remain under pressure for some time.
The health and growth prospects of Britain’s defence industry is likely to play heavily on politicians’ minds
Employing over 300,000 people directly and indirectly, Britain is the world’s second largest exporter of defence equipment and services after the United States, with exports netting 8.8 billion pounds in 2012.
“If we don’t spend the money on defence and buy equipment ourselves and equip our forces well, why should anybody buy from us?,” Wheeldon asked. ($1 = 0.5877 British Pounds) (Additional reporting by David Milliken; Editing by Tom Heneghan)