Meghan Markle joined other members of the Royal Family at the Cenotaph war memorial in London to pay her respects to those who have lost their lives as a result of war.
The Instagram post was described as “disrespectful” as users said the designer was using Remembrance Sunday to sell clothes.
The post, which has now been deleted, spoke of McCartney’s pride that the Duchess of Sussex chose to wear her £1,500 autumn 2019 coat for the occasion.
The post said “So honoured to have HRH Duchess of Sussex in our Autumn ‘19 coat at Remembrance Day service x Stella.”
Meghan stood alongside Countess of Wessex and Vice Admiral Sir Tim Laurence at the service as Prince Harry laid a commemorative wreath.
Some viewers were confused as to why Kate Middleton and Meghan Markle were standing on separate balconies, which was to do with royal protocol rather than hints of an ongoing rift.
Fans of the designer praised the elegant style of Meghan’s outfit as well as the design of the coat.
However, other Instagram users found it disrespectful, claiming McCartney was using the Remembrance Sunday ceremony to sell her designs.
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“Using Remembrance Day to advertise your clothes is a little disrespectful! People died and you take pictures of people showing respect for advertising purposes. Just wrong.” One comment read.
Another said: “Today is about those who gave their lives for our freedom. Who gives a f*** what she’s wearing.”
Others branded the post “tacky” and “surprising”.
A short time before posting the picture, McCartney posted a video of poppies in a field with the caption “Remembering the ones that sacrificed to give us freedom x Stella.”