Katherine Jenkins almost suffered a royal fashion faux pas when she realised her Union Jack dress designed for Queen Elizabeth’s 90th birthday concert looked more like the French flag.

The opera star performed for the monarch at a special concert in the grounds of Windsor Castle in 2016 wearing a red white and blue gown designed by Suzanne Neville - but discovered at the last minute the dress had a major flaw.

Katherine told Britain's HELLO! magazine there was a rush to fix the gown before she took to the stage, explaining: “I look back at that dress with great fondness and stress.

“I had an idea to make a dress especially for the occasion that looked like the Union Jack. When I went to the fitting the day before, the underneath of the cape was white and when I turned to the side, I realised it looked more like the French flag.”

The singer admitted they had to hunt down a real flag and have it sewn into the dress to make sure there was no confusion.

She added: “In the end, we hunted down the biggest British flag we would find and had it sent into the cape to be sure the correct country was honoured.”

Katherine has performed for the Queen on many occasions over the years and recalled the first time she met the monarch she was given an introduction by her late husband Prince Philip.

The singer revealed: “I remember meeting the Queen and the Duke of Edinburgh in the line-up and him introducing me to Her Majesty as ‘the girl that sings at the rugby’.

“It doesn’t matter how many times I perform for her or meet her, whether it’s in front of thousands or just at a small dinner, I’ll never be blasé about it.”