It's difficult to tell these two little boys apart thanks to same cheeky smile

They share the same side-swept fair hair and cheeky smile, and when they’re perched on steps wearing knee socks and pullovers decorated with Grenadier Guards, it’s royally difficult to tell these two little boys apart.

But one is HRH Prince George of Cambridge, third in line to the throne and born into a life of palaces and privilege – while the other is plain old Tommy Cox from Colchester, Essex.

Two-year-old Tommy’s mother – whose name, as it happens, is Kate – and father Paul, 41, are regularly stopped by people who want to have their photograph taken with the prince’s lookalike.

Keen royal watcher Mrs Cox is always keen to see each new photograph of George when it is released by his parents William and Kate to check if the two boys from very different worlds are continuing to grow up looking the same.

She said: "They both have the same brown eyes and lovely, rosy, chubby cheeks and when Tommy's hair is in a side parting, it is uncanny how the two boys look so similar."

Tommy, who celebrated his second birthday on March 8, is slightly older than George, who will be two on July 22.

Friends of Mrs Cox have suggested she should look into getting work for Tommy as a royal look-a-like, some of whom can earn up to £1,000 a day.

But she is not keen - as she admits her son’s behaviour sometimes falls rather short of regal.

She said: "I might look into it, but to be honest, Tommy does not follow orders too well."

"I do call him my little prince sometimes but his behaviour is not that of a royal."

"At nursery they describe him as 'busy' and he is always rushing around and exploring. He is very excitable."

Mrs Cox added that her husband was not even aware of their son’s claim to fame.

She said: "Paul is not a fan of the Royals so when his mum started telling him how Tommy looked like Prince George, he had to look for pictures of him to see what she was talking about."

The real George, of course, is due to become a big brother at any moment – and in a very modern move, the birth will be formally announced on royal social media accounts before a notice is posted on the traditional easel outside Buckingham Palace.