The couple made their relationship public earlier this year, shortly after the end of Peter’s relationship with Lindsay Steven.

Peter and Harriet have made a series of joint appearances this summer, however, they were separated in August for a short while as Princess Anne’s son spent time in Scotland, while Harriet stayed in England for work.

Peter joined the rest of the royals at Balmoral alongside his two daughters he shares with ex-wife Autumn Kelly – Savannah, 13, and Isla, 12 but without his new girlfriend.

A source told Express.co.uk that Harriet could not join Peter in the Scottish Highlands as she had to return to work.

They said: “Harriet and Peter have spent a lot of time together over the summer and Harriet has had to go back to work.

“Peter has taken his girls to Balmoral and is spending time with the family as he does every year.”