How Harry and Meghan earn 'clean money' will be difficult, says PR consultant

Some commentators have argued the existing model of royal wage earners such as the Queen's grandchildren Peter Phillips and princesses Beatrice and Eugenie could be the example they follow.

Public relations and crisis consultant Mark Borkowski said there were pitfalls ahead for the couple, adding: "The problem is how do they get what we call clean money.

"Because there will be meat for the media if they are sponsored by a famous watch company and turn up at a royal event wearing that watch, or take a flight on a new airline route, or get hypnotised by some odd person who wants to be associated with them and they've got funny - not clean - money.

"So that's going to be the challenge, how they balance the money and the funding they want from the corporate world against still having the sheen of the royal family. It's a difficult thing to navigate, to keep credibility for everything you do."

Reports have suggested the Sussexes may follow the lead of their famous friends Barack and Michelle Obama, the former US president and his wife, and their counterparts Bill and Hillary Clinton who have capitalised on their time as international figures.

With her combination of royalty and Hollywood glamour, Meghan would be highly prized by any publisher wanting a tome about her time at the centre of the monarchy or even her thoughts about topics close to her heart, such as gender politics and female empowerment.

The well-paid lecture circuit is also available and may better suit Harry, an accomplished speaker who, with his Army training in leading others and experience of appearing on stages across the world, could become an in-demand motivational speaker.

Meghan's defunct lifestyle blog The Tig could be revived to give her a platform to talk about everything from fashion to food and would attract advertising.

There could be an ethical dimension to their work, with the couple signing up to financial projects or endorsements that promote a cause or highlight an issue that chimes with their own beliefs.

The duchess has already begun her life in the commercial world narrating a new Disney film about a family of elephants and their journey across Africa available to stream from April 3.

She will not receive a payment - Disney will make a donation to the wildlife organisation Elephants Without Borders supported by Harry - but it will be a calling card to other global entertainment companies.

The couple faced criticism after video footage emerged of Harry at the premiere of The Lion King in London last July, praising Meghan's ability to do voiceover work to the then head of Disney Bob Iger.

It is thought Charles will continue to offer some financial assistance to his son and daughter-in-law.

Meghan has reportedly kept her Hollywood agent, lawyer and business manager so there is a team in the wings to put into place any financial plans the Sussexes devise.