Royal watchers slam Duchess of Cambridge over Alexander McQueen 'prom dress'

Kate also chose to wear one of Diana's tiaras. Photo / Getty Images

Dressing for the pomp and splendour of a state banquet is a tough challenge, and according to royal fans the Duchess of Cambridge got it wrong as she attended a glittering event to welcome the Dutch royals last night.

Kate, 36, chose a ruched Alexander McQueen gown with a drop waist and fishtail skirt for the occasion, but according to the Daily Mail, some commentators said the gown looked a lot like an '80s bridesmaid or prom dress.

Kate was slammed over this look. Photo / Getty Images

"This dress is maybe the worst Kate ever wore. It's shocking, actually, she really needs a fashion makeover," one wrote.

Another said they would not have been surprised if she'd borrowed it from the current exhibition of Princess Diana's vintage dresses at Kensington Palace.

"Normally I'm a fan of what Kate wears, but this is truly awful,' another said. 'What was she thinking."

Another royal watcher claimed that Princess Charlotte might have asked her mother to dress up like Elsa from Frozen, while one said her childhood Barbie used to wear a dress just like it.

A woman noted that it looked similar to a bridesmaid dress from 1985. Photo / Twitter

The last time Kate's dresses caused such controversy was she stepped out in "frumpy" floral dresses by Erdem two nights running during the royal tour of Sweden in January 2018.

Last night Kate joined husband Prince William, 36, and other senior royals for the lavish dinner hosted in honour of King Willem-Alexander and Queen Maxima of the Netherlands.

As per protocol, female members of both the Dutch and British royal families donned ballgowns and tiaras for the event.

Making her third appearance at a state banquet, the Duchess of Cambridge chose a dusty blue gown by favourite designer Alexander McQueen.

The dress - made in a thick vintage-inspired fabric - featured a ruched bodycon fit on the torso and flared out in a fishtail style.

The duchess finished the look with the diamond and pearl Cambridge Lover's Knot tiara owned by Princess Diana, which she also wore to the Chinese state banquet in 2015 and the Spanish state banquet last year.

She added extra wow factor with Diana's Collingwood Pearl and Diamond Earrings and the diamond and pearl Queen Alexandra Wedding Necklace, on loan from the Queen.

It was a favourite piece of the Queen Mother's but hasn't been seen publicly since the monarch inherited it.