As England gears up for tonight's semi-final match, people across the country are aping Gareth Southgate and proudly wearing waistcoats to work.
The surprise trend has gripped the nation, with M&S selling out of most sizes of its signature blue waistcoats, after being appointed the official tailors for the England football team.
The store is now almost completely sold out with, as of last night, only XXL sizes of M&S’s slim fit navy waistcoat – which costs £65 –left online.
The craze has even hit Russia, where Moscow branch of M&S had run out of most sizes of the waistcoat.
Ivan Novikov, 25, a Moscow tax consultant, bought one, costing 3,999 Roubles(£50) yesterday after watching the England manager on Russian television.
“I saw him at England versus Colombia and I thought: ‘he looks good,” said Mr Novikov, “I don’t even know his name.”
Mr Novikov believes the waistcoat will become a must-have fashion accessory among Russia’s younger workforce.
Former Strictly Come Dancing star Brendan Cole joined in, sharing his support for the England football team ahead of their World Cup semi-final against Croatia.
The New Zealand dancer shared pictures of himself wearing waistcoats, in honour of waistcoat-wearing England manager Gareth Southgate, on Instagram.
He wrote: "COME ON ENGLAND!
"I've been supporting England for years according to to these waistcoated photos! #waistcoatwednesday #garethsouthgate #comeonengland."
Richard Branson also got in on the action:
Cancer charity Bloodwise has asked fans to wear waistcoats to work and donate £5 to the charity in support of the team.
Offices across the UK are flooded with workers sporting their favourite waistcoats - some more jazzy than others:
@rachelburden@bbc5live For #WaistcoatWednesday & for 3 lions! 3 handmade Harris tweed waiscoats by my wife. Buttons for my son and I are in the mail! (She made the map, too!)#CROENG#ComeOnEngland#GarethSouthgate#bbcworldcup#WorldCup#ENGLANDpic.twitter.com/usGOjf8hm1— James Wren (@jameswren1975) July 11, 2018
Meanwhile, England fans in Russia have also been seen sporting waistcoats, and Doncaster Council, in the north of England, even hoisted a waistcoat on its flagpole.