First there was the return of the pant suit, spearheaded by Lady Gaga on stage and Hillary Clinton in Congress. Now the latest version of the trend is a far more relaxed affair, and it’s set to be the look of the summer.

Short suits – oversized blazers paired with coordinating loose-fit tailored shorts – are this summer’s power suit.

It’s a look that is gaining ground on websites like Asos, where women’s suiting sales have increased 400% over the last month. While this includes the classic trouser combination, the brand’s grey pinstripe short suit alone sold 195,000 units in the space of a week.

During the last week of March, searches for short suits at fashion search engine Lyst also increased by 19% in the UK, with Maje and Stella McCartney featuring among the most viewed brands.

“Tailoring is one of the key trends of the season, and as the weather is warming up the newest way to wear the trend is the short suit,” says Ida Petersson, buying director at the London boutique Browns. “A bit more daring and way more fun than a skirt or trouser suit, this is the perfect option for the unpredictable spring weather in the UK as it both reveals and covers simultaneously.”

Asos has labelled its bestselling short suit a “mom” suit, reminiscent of the high-waisted, loose-fit “mom” jeans that have dominated the high street in recent years. If that makes it sound a bit 1980s, that’s because it is.

Julia Roberts nails the look in Pretty Woman. Photograph: Allstar/Alamy

Last month Julia Roberts said she didn’t think Pretty Woman could be made today but the film’s fashion, at least, has proved itself forward-thinking: Vogue recently named her character, Vivian Ward, as one of “10 throwback movie muses who are totally on-trend for SS19”, specifically citing her “sorbet-coloured city shorts with boxy blazer”.

“She needed something that wasn’t jeans or messy hair, where she looked ladylike but also relaxed and not over the top,” says Pretty Woman costume designer Marilyn Vance of the outfit Roberts wears at the poolside in the film. “It’s the perfect outfit for today because people are less businesslike now. It could be worn with a blouse to the office, collar open with a little necklace. It’s conservative but cool.”

On the catwalk, boxy, metallic blazers were recently paired with matching shorts at Emporio Armani, while both House of Holland and Off-White showcased longline short suits in summery citrus tones.

Menswear has long sought to include shorts within its suiting options, but this year it’s primarily a womenswear trend.

On the high street, linen-blend short suits come in earthy tones (as well as bright red) at H&M, while Mango pairs blazer jackets with Bermuda shorts.

The rise of this look could also be attributed to cycling shorts, 2018’s trickiest trend. Net-a-Porter describes teaming them with an oversized blazer as an example of hi/lo dressing and an “80s-athleisure mash-up [that] shouldn’t work” but does.

Crucially, this summer’s short suits are not the thigh-flashing numbers of the late 00s, many of which graced the red carpet paired with stiletto heels (see Kate Winslet and Beyoncé). Rather than short shorts peeking out from beneath buttoned-up blazers, both jackets and shorts are being worn long and – bar the presence of Lycra – loose-fitting.

Fashion bloggers and influencers, such as Hannah Whiting and Tiffany Hsu, have tended to pair theirs with chunky trainers and plain cotton T-shirts for what could well be the answer to this year’s “smart-casual” dress code conundrum.

“Sneakers, T-shirts and a cool belt would make a short suit look sporty,” says Vance. “But you could also pair it with a beautiful little halter-neck top for the evening. It’s very adaptable.”