Something has happened to Preen. Something great. Ruth Chapman, the influential buyer of Matches, who buys the label, put it simply after the show: ‘They’ve absolutely hit their stride.’

If you saw Preen’s pre-fall collection – all tartan, zips, red and black, a concise deconstruction of wearable punk – you won’t be surprised to learn that they evolved this chic punk for their mainline collection, shown this morning at the top of Heron Tower overlooking the City.

Like Clements Ribeiro, who showed on day one of LFW, these long-established designers had also been looking back at their archive where they discovered a certain tutu stitched to a t-shirt. This, and Derek Jarmon’s post-apocalyptic New Wave cult film, Jubilee, provided the inspiration.

The palette was red, black and white, which served to emphasise Justin Thornton and Thea Bregazzi’s slick, cool silhouettes. These designers have developed such an instantly recognisable style with their zippered coats, narrow trousers, nod-to-couture dresses, that every piece looks unmistakably theirs. They had cleverly worked in the punk theme – bum flaps that can be zippered off trousers for a more conservative look if need be and the idea of the tutu t-shirt reworked into voluminous front or back skirts – without it ever overshadowing the specialness of the clothes.

And how special. The last series of harlequin crystal pieces looked exceptional – and expensive. That’s another red thread running through London Fashion Week – decadent polish – and it was here, too, in the long sweeping dresses printed with leopard spots that ended up as abstract digital fragments to the modern glamour of their streamlined tailoring. The only answer, if you want to buy these pieces, is to save all season.

As for hitting their stride, has it something to do with showing back at LFW, after so many years in New York? Bregazzi, who was heavily pregnant with her second child when the couple showed last season (and gave birth to daughter Blythe a few days after the show) said she was working part time now and this had given her a fresh perspective.

‘When you’re in it all the time it’s sometimes hard to see, but now I can focus, see it all clearly.’ Whatever the reason for Preen’s absolute clarity of vision, it’s certainly working.

See the full collection here