Prince Harry and Meghan Markle's new approach to promoting their projects separately is down to the fact that their Sussex brand has become "toxic" through the years, a PR expert has claimed.

The Duke and Duchess of Sussex made a string of solo appearances this month in what has been seen as a new take on their "dynamic".

Harry went on a solo tour to New York, London and Southern Africa to promote his own causes, while Meghan was seen attending events on her own which held special links to her projects.

Now PR expert Ed Coram James claimed that the Sussex couple's brands are stronger as individuals rather than as a couple after their joint ventures turned out to be "toxic and thus commercially untenable".

He told GB News: "Since their marriage, Harry and Meghan have had a distinct brand. That brand is based on a duo.

"Call it 'Harry and Meghan', call it 'the Sussexes', call it whatever you like. The fact is that for years they have become synonymous with one another.

"And, since the famous Oprah interview, in which they took a simmering disagreement between themselves and the rest of the Royal Family and essentially declared all-out-war, that brand has been steadily becoming more toxic and thus commercially untenable to the point where not that many major brands are going to be rushing to write them a large cheque based on their brand value.

"When combined, the Sussexes brand is, from a PR perspective, toxic. But, when separate, they have a genuine chance of creating an entirely separate brand, with completely different labels."

Meanwhile, Sky News Australia senior reporter Caroline Marcus agreed and said Harry and Meghan's initial strategy of jointly speaking against the royals made the public perceive them negatively, which is a scenario that is unlikely to change any time soon.

She said: "The contrast [between Harry and Meghan's ventures and the King and Queen's latest royal tour] is so stark because that sense of duty the King and Queen have compared to these two pretenders who couldn't even master enough enthusiasm for the Royal Family, the traditions that Harry was lucky enough to be born into and Meghan to be married into, it's just put off so many people".

However, the latest shift in the couple's business strategy was dubbed as a "twin-track approach" by one of their friends, according to People.

An insider echoed the statement and told the publication: "The Duke and Duchess have now hit their stride as individuals – not just as a couple. The Duke appears focused on his patronage work, and the Duchess focused on her entrepreneurial track."