Royal Ascot updated its dress code to allow jumpsuits for the first time in 2017, and this year male racegoers are getting an update to their dress code as the most fashionable event of the summer social season.

For the first time, navy morning suits will be permitted in the Royal Enclosure for the relaxing the strict rule for men to wear either traditional black or grey, and more 'playful' ties will also be allowed.

This year, the world-renowned Ascot Racecourse in Berkshire has also sought sustainable brands for its ninth annual Style Guide in association with luxury cruise brand Cunard.

The guide predicts pastels and florals will be the key trends of the summer alongside innovative millinery, and with an emphasis on being eco-friendly female racegoers are being encouraged to buy second hand or rent their outfits.

ROYAL ENCLOSURE

Recognising emerging trends in formal menswear, navy morning suits are permitted in the Royal Enclosure for the first time. Top Hat: Oliver Brown, from £600. Man's shoes: Fairfax & Favor, £215

Hat: Edwina Ibbotson, £3,500 Dress: Suzannah, £1,850. Bag: Aspinal of London, £450. Shoes: Jennifer Chamandi, £550

Hat: Jane Taylor London, £716. Dress: Roland Mouret £,1895. Shoes: Manolo Blahnik, £825. Emerald and diamond ring: Garrard, POA (left). Right: Hat: Philip Treacy, £3,420. Dress: Solace London, £590. Shoes: Manolo Blahnik, £775

This year feathers, pastel-toned sequins and statement floral suits with metallic accents are some of the fashion highlights for women in the coming season.

Ethical and green brands are at the heart of the 2020 Guide which champions reselling sites where members pay to rent outfits which are changing the fashion landscape.

To make it easy for racegoers to dress to impress, and to the standards, the Style Guide has been broken into each enclosure and suggested outfits for each.

QUEEN ANNE ENCLOSURE

There is a more relaxed dress code in the Queen Anne Enclosure where men don't have to wear morning suits, but strapless or sheer dresses are not permitted

Floral prints feature in the 2020 Style Guide with this pastel blue dress suitable for the Queen Anne Enclosure (left). Feathers and soft tones feature throughout the Style Guide (right)

Hat: Rachel Trevor-Morgan, £845. Suit jacket: £1,880, Trousers: £1,180, Mark Katranzou. Shoes: Emmy London, £395 (left). Right: The Queen Anne Enclosure has slightly more relaxed rules in comparison to The Royal Enclosure. Peach and lilac tones echo the pastel tones for the season. Hat: Ana Bella Millinery, £280. Dress: Christopher Kane, £1,495. Shoes: Kalda, £270

The exclusive Royal Enclosure, which is often described as 'the heart' of the event, has always had tight rules.

In previous years, it has insisted attendees cover their midriffs and avoid wearing fascinators and that still stands.

Hats should be worn in the Royal Enclosure with the base of a headpiece measuring at 4ins (10cm) or more in diameter while fascinators are not permitted.

WINDSOR ENCLOSURE

Hat: Debenhams, £90. Top: £79 and skirt £119, Ted Baker. Belt: £69 and shoes: £139, both Hobbs (left). Hat: Debenhams, £150. Blazer £65, waistcoat £45, shorts, £36, River Island. Shoes: Boden, £110 (right)

Classic tailoring is a key trend for men at Royal Ascot. Classic tailoring is a key trend for men at Royal Ascot. Pictured: Blazer: £275, Shirt: £85, Trousers: £125, Shoes: £175 all from Reiss (left). Right: Headband: Boden, £15. Dress: Reformation, Hurr Collective, £61 for one week's rental. Shoes: Sandro, £239

Subtle metallic nude is the perfect ensemble for the Windsor Enclosure (left). Navy is a standout trend for men in the Style Guide with this tailored suit for the Windsor Enclosure (right)

The Queen Anne Enclosure has slightly more relaxed to the Royal Enclosure yet strapless and sheer dresses are not permitted.

A formal dress code was introduced for the first time in 2018 for the Windsor and Village Enclosures and a hat, headpiece or fascinator must be worn at all times.

Featured looks in the Style Guide this year include designs from Roland Mouret, Christopher Kane, The Deck, Mother of Pearl, Suzannah, Huishan Zhang and Temperley London.

Menswear sees a fashion milestone for 2020 with navy morning suits introduced for the first time in the Royal Enclosure.

And to celebrate the key date for 2020, official licensee Favourbrook has designed an exclusive collection that features a superfine merino wool navy three-piece morning suit found on the cover of this year's Guide.

VILLAGE ENCLOSURE

Bold metallic and silver tones make a standout feature and are suitable for the Village Enclosure in the 2020 Royal Ascot Style Guide

The Village Enclosure introduced a formal dress code for the first time in 2018 and a hat, headpiece or fascinator must be worn at all times

For men, classic tailoring, light double breasted suits with playful ties and soft pastel tones are at the forefront of formal wear for this year's racing event.

How To Dress Well For Ascot Royal Enclosure Dresses and skirts should fall above the knee or longer Dresses and tops should have straps of one inch or greater Jumpsuits are welcome, but should fall below the knee Trouser suits welcome, but should be full length and of matching colour Headpieces must have a solid base of four inches or more Queen Anne Enclosure Strapless dresses or tops are not permitted A hat, headpiece or fascinator should be worn at all times Trouser suits must be full length, jumpsuits should fall below the knee, shorts are not permitted Village Enclosure One shoulder dresses, strapless tops and bardot are nor permitted A hat, headpiece or fascinator must be worn at all times Trouser suits are welcome, they should be of full length and matching colour Jumpsuits are permitted but should be below the knee Windsor Enclosure Dress for a formal occasion, with a hat or fascinator Advertisement

Working closely with stylist Prue White, Ascot has curated looks that were captured by world-class fashion photographer Carla Guler for all four Royal Ascot Enclosures.

The Royal Ascot Style Guide features millinery from the likes of Philip Treacy OBE, Jane Taylor, Awon Golding, Lock & Co, William Chambers Millinery, Sarah Cant, Edwina Ibbotson, Rachel Trevor Morgan and Julian Garner.

Juliet Slot, Chief Commercial Officer, Ascot Racecourse, said: 'Royal Ascot sets the trends for event dressing across the summer season and we're really pleased that we are recognising both British designers and sustainable fashion as key 2020 trends in this year's Royal Ascot Style Guide.

'Each year we carefully curate a selection of fashion-forward looks suitable for each of the four distinctive enclosures.

'We are also delighted to have included a number of sustainable labels this year, in-line with the changing face of global fashion, and rental and resale sites that are set to continue growing in popularity.

'This year's team has delivered a strong edit of key looks which, combined with the best of British millinery, will maintain Royal Ascot's position as the ultimate fashion event in the racing calendar and continue to shine a global spotlight on summer style.

'We are extremely grateful to Cunard for their continued support as we continue our brand partnership for a third year.'

This year's Royal Ascot runs from June 16th to Saturday 20th.