After spending 35 years as official corsetiere to the Queen, what June Kenton doesn't know about bras isn't worth knowing.

And the former owner of luxury lingerie brand Rigby and Peller - which holds the Royal Warrant - says at least 85 per cent of women are wearing the wrong size.

Expert June, who never uses a tape measure and can assess a woman's cup size by sight alone, shared her top tips for achieving the perfect fit in an appearance on ITV's This Morning today - right down to which hook to use to fasten your bra.

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June Kenton, 81, appeared on This Morning to share her top tips when it comes to finding a bra that fits perfectly

She has been the Queen's official corsetiere for 35 years and has a wealth of knowledge about the mistakes women are making with their underwear

June has written a book about her time as Her Majesty's bra fitter. She sold her lingerie company Rigby & Peller - which holds a Royal Warrant of Appointment

June explains that the bra strap should be level with your underwire and that the bra should be flush with you chest

June assessed the fit of bras modelled by two women on the show today.

She explained why full-busted model Hannah's ill-fitting bra was all wrong for her.

TIPS FIT FOR A QUEEN All women should be fitted by an expert The right bra will feel as though you're not wearing one All women should wear bras with underwire The underwire should be flat against the chest The bra strap on your back should be level with the underwear and be worn on the first hook Go up in cup fittings only - not whole sizes Always hand wash bras Advertisement

'She is hanging out of it anyway,' said June.

'But if she lifts her arms up she would come out underneath.

'When you are wearing a bra you should not have to re-organise every time you move,' she said, explaining that ideally a woman should 'not know' she is wearing it.

June added that if a woman is worrying about her lingerie, it's because she's wearing the wrong size.

She explained that everybody needs a bra with underwire, which should fit flat against the chest in order to provide full support.

She joked: 'You grew two [breasts] why do you need six?

'Why be greedy you should be in the cup.'

June added that a woman should go up cup fittings and not whole sizes, and that the strap's position on the back should be level with the underwire at the front.

Bras should be fastened on the first hook, she said.

The Queen's corsetiere also advised women to invest in high quality bras and to always hand wash them so they last as long as possible.

Her Majesty's official bra supplier since 1982, June shared her top tips for women who make common mistakes

This Morning airs weekdays on ITV at 10.30am