FORD Dunton has rolled out the red carpet for prime ministers and a prince in the past.

But as the motor giant's research plant officially celebrates its 40th anniversary,the emphasis has shifted firmly to another colour - green.

The UK's biggest automotive research and development facility, near Laindon, has been working to create and refine the cars so many of us drive for 40 years.

Opened by Prime Minister Harold Wilson on October 12, 1967, it cost Ford £10.5 million to build - a relatively small amount by modern standards, but a vast sum back then.

Times may have changed, but Ford Dunton workers' commitment to their jobs remains as strong as ever.

Today (Friday October 12) about 3,000 staff work on the site, which has given birth to many of the great British driving public's favourite motors, such as the Fiesta XR2, Escort Cosworth and Sierra XR4x4.

More practical classics such as Ford Granada - and of course, the Transit van - first took shape in the design offices and test facilities of Dunton.

Prince Charles paid an official visit to the site in July, at the start of the formal celebrations.

Today workers are due to let their hair down with a party to mark the centre's outstanding work.

Every employee is to get a brochure about the site's history, while the sounds of the Sixties are to be heard, courtesy of a tribute band called the Bandit Beatles.

After the party, it will be back to work - with top priority accorded to the global fight to cut carbon emissions. The centre is leading the field in developing greener motoring options.

Ford's new Econetic range of cars will produce as little as 99 grammes of carbon dioxide per kilometre - a third of the amount pumped out by the average conventional car.

In July, Prince Charles planted the first of 40 new trees at Dunton, to mark the start of the celebrations. Today, the centre's head, Graham Hoare and predecessor Malcolm Thomas, will put in the final tree.

John Fleming, the head of Ford in Europe, is also coming down to spend the day at Dunton, visiting the engineering team, which specialises in engines and transmissions for the vehicles of the future.

He said: "Our award-winning products and powertrains are continuing to win acclaim around the world and Dunton is the centre of excellence behind many of them.

"The success of our commercial vehicles - the Transit was International Van of the Year 2007 - is key to our sustained profitability.

"There are many so-called technical centres in the UK, owned and operated by car companies. But Dunton is the biggest, and the most established."

During his visit the Prince of Wales, who is well known for his interest in all things green, was given a behind-the-scenes glimpse of Ford's future environmentally-friendly products.

He drove a Ford Focus, fitted with a prototype low-carbon dioxide engine, developed in Dunton's environmental test laboratories, where vehicles are cold and hot weather tested.

The car is one of the next generation of Fords being developed as the result of a £1billion investment in environmental technologies in the UK, announced last year - with Dunton the main centre for this work. Basildon MP Angela Smith is a fan of the firm's green offerings.

On a visit earlier this year, the Labour MP drove a Ford Focus flexible fuel vehicle - capable of running on petrol, or biofuel.

Ford Dunton head Graham Hoare added: "His Royal Highness was among the first to champion environmental issues.

"We shared with him Dunton's green technologies - including engines and transmissions - currently available or being engineered for future applications."