VIDEO: Duke of Cambridge "looking forward to seeing more McLarens on the road"

Also opening the factory alongside the Royals was The Crown Prince of Bahrain, Prince Salman bin Hamad bin Isa Al Khalifa, who is one of McLaren’s main shareholders.

The royal party were the first guests to sign the visitors’ book at the end of the hour-long tour (pictured below).

The Duke and Duchess landed at Brinsworth at 11am via helicopter onto the Phoenix Sports and Social Club playing fields.

They were whisked alongside police escort to the McLaren factory where they were greeted by Her Majesty’s Lord-Lieutenant of South Yorkshire, Mr Andrew Coombe.

Rotherham council leader Chris Read and the Mayor and Mayoress of Rotherham were among the first to greet the couple as around 100 fans watched on.

Sarah Sanders (35), of Whiston, had arrived at McLaren at 9am along with her 20-month-old son Noah.

Sarah (35) said: “I just wanted to catch a glimpse.

“I wouldn’t say I’m a huge fan but I do like following them and it’s not often they come to Rotherham.”

Natalie Clark also braved the cold with son Callum (2) and dog Kyle and said it was a chance for her son to see the future King of England.

The Royal Party was given a tour of the factory floor by Ruth Nic Aoidh, McLaren’s executive director for commercial, and Mike Flewitt, McLaren CEO.

The site aims to be a world leader in innovating lightweight carbon fibre tubs that are integral to the agility and performance of McLaren’s supercars and sportscars.

As the couple made their way out of the McLaren factory, Prince William said he “looked forward to seeing more of them on the road” and Kate Middleton wished the team the best of luck for the future.

Mr Flewitt said the royal visit had been around six months in the making and had worked out well as The Crown Prince was in the country to join Prince Charles this evening for his 70th birthday party. 

“It’s such a proud day in two ways,” said Mr Flewitt.

“We are proud of what we are doing, the technology here — we’re the only company in the world doing this which makes our cars incredibly special and we’re doing it all in-house.”

He said Their Royal Highnesses had been keen to hear about the firm’s green credentials but were “more interested in the people”.

The chief executive said he hoped the royal recognition would make the employees proud.

The opening celebrations were set continue into the afternoon as employees’ families were invited onsite for further tours of the pioneering centre.