Why have Harry and Meghan hired a social media expert?

Prince Harry and Meghan, Duchess of Sussex, during a photocall with their newborn son.

Prince Harry and Meghan have opened a new front in the battle for online supremacy.

The couple, who are establishing their own household after splitting with Prince William and Kate, have parked their 'social media tanks' on the Duke and Duchess of Cambridge's lawn by recruiting an online whizz to boost their popularity globally, the Dialy Mail reports.

'They have appointed a new member of staff to work on their social media accounts,' a royal source tells me. 'The new person will start in time for Meghan's return from maternity leave.'

Although officials are keen to play down any rivalry with the Cambridges, the Duke and Duchess of Sussex have attracted a staggering 8.5 million followers since they launched their Instagram page in April, only 700,000 fewer than William and Kate, who joined in 2015.

Just last month, Harry and Meghan shared unseen photographs from their wedding on Instagram, on the same day as Kensington Palace tried to use the picture-sharing website to celebrate Kate's garden design at the Chelsea Flower Show.

The Sussexes' online enthusiasm has caused surprise as Harry previously claimed social media was more addictive than drugs or alcohol. Meghan was, though, enthralled by social media while she was still an actress.

All smiles between the families irl, online it's a different story...

A spokesman for the Duke and Duchess declines to comment on the appointment, but the new recruit will join a growing team of 'spin doctors'.

They have already appointed Sara Latham, a former adviser to Hillary Clinton, as their communications secretary and Julie Burley as senior communications officer.

Before Meghan married into the Royal Family, courtiers expected she and Harry would work closely with William and Kate as a 'Fab Four'.

In the battle for followers there's not much in it

However, the two households have since split, with Harry and Meghan moving to Frogmore Cottage in Windsor and appointing their own staff.

Their charitable foundation is also to be split, and newly published accounts reveal the huge amount of money at stake.

It raised £7.83 million last year, on top of £9 million in 2017.