The M&S dress worn by Holly Willoughby we predict will sell out

The Holly Willoughby-approved dress will definitely sell out this autumn. (Getty Images)

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While September seems to have finally graced us with some sunshine, we all know that soon enough, it will be time to dig out those tights, thermals and puffer coats.

If you're a savvy shopper you'll know now is the best time to add to your autumn wardrobe, so you can bag all the best items before they sell out - and our top priority is finding a flattering dress to see us through the season.

Well, we've searched high and low, and finally found the Floral High Neck Midi Tea Dress from Marks & Spencer, a brilliant transitional piece, particularly when we aren't sure whether it's going to be sweltering or freezing, and a dress that will slot easily into your wardrobe for years to come.

Plus, we're not the only ones who have our eye on it - the new-in M&S number has already been approved by Holly Willoughby, who wore it to host a Sparks Live event on Wednesday evening to talk through the best new autumn styles.

Holly Willoughby attends the Marks & Spencer Autumn Winter 21 seasonal launch event. (Getty Images for Marks & Spencer) (Getty Images for Marks & Spencer)

If you cast your minds back earlier this year and remember how fast that statement floral puff sleeve dress sold out after it had been worn by Willoughby, we have no doubt that this is will the autumn equivalent.

Why we rate it:

Let's start with the silhouette - the affordable £39.50 midi dress features a high neckline and empire-line bodice to create a flattering and elegant shape.

Available in three different floral prints, you’re bound to find the tea dress in a pattern that suits you.

The dress also has some lovely finishing touches, including dainty frilled cuffs on the long sleeves and a subtle back zip so you can easily throw it on.

The dress comes in three different prints. (Marks & Spencer)

From a feminine pink design, to more classic muted monochrome, there's bound to be a print to suit you. (Marks & Spencer)

The dress is super versatile and can be styled in numerous ways. (Marks and Spencer)

Plus, the number is incredibly versatile to style - and for under £40 is sure to get great cost per wear.

Looking for an edgy outfit? Buy the black mix and pair it with a biker boot and leather jacket. Looking for an outfit for a - slightly chilly - garden party? Buy the pink mix and pair with some white loafers or slingbacks.

Each design is currently available in sizes 6 to 24 (though we can't promise that will be the case for long).

What the reviews say:

It may have only just dropped on M&S' website, but it's already racking up five-stars across the board, with customers praising it for its flattering silhouette and statement prints.

"The style of this dress is just perfect for me. I am a size 12 and this dress seems to conceal and flatter in the right places. The fabric is pretty and I think it is great value for the price. I think that this style would suit and flatter most sizes. Well done, M and S."
"The pictures don’t do this dress justice! It’s a great combo of 1940’s style with a 70’s print. I love it."
"This is a great dress! The sizing is spot on, pretty print, easy care viscose. Will wear with sandals now, boots later. A good transitional piece. Liked it so much, I got the similar one in black/turquoise print. I bought the regular length, as I find it's a better length for a tea dress. Mid calf on my 5'8 frame. More like this please, Marksies!"
"I have just purchased this dress, lovely dress for work."