Kate Middleton's brother James is back on the market following split from Donna Air

It appears that the job for future sister-in-law to the future Queen of England has opened up. James Middleton, younger brother of Catherine, the Duchess of Cambridge, has reportedly ended his two-and-a-half year relationship with 36-year-old actress Donna Air.

The couple, who began dating in February 2013, allegedly broke things off a couple of weeks ago, according to a source who spoke to The Sun's Dan Wootton. "The split happened a couple of weeks ago and it was James's decision," the source said.

Air is said to be "more than a little heartbroken" by the 28-year-old's decision to call their relationship off and has been lying low since the split, the Daily Mail reported.

The source continued: "He just didn't think it was going to go the distance. And I think his family were always very anti her being the future Queen of England's sister-in-law." The blonde former host of Big Breakfast hinted at the rumoured break-up with an inspirational message on her Instagram. "Accept what is, let go of what was, have faith in what will be (even those itchy ears)," the message said.

According to the Daily Mail, news of the break-up comes as bit of a shock following the couple's display of affection during their Caribbean holiday with the Middleton family in St Barts in August. The rumoured split also comes just days after Air's grandmother passed away.

The twosome went public with their relationship in 2013 but remained relatively private throughout their romance. The Daily Mail noted that while the couple is rarely seen out together, they had displayed their love on social media a couple of times.

Air was last spotted speaking to her former partner Damian Aspinall along with their daughter Freya.