#WAISTCOAT WEDNESDAY is the hashtag The Sun deploys in its headline and calls on fans to "Dress like Boss for Semi".
"The Sun today urges Three Lions fans everywhere to smarten up and follow our fashion leader into battle in Moscow," is its tub-thumping message.
Sister paper the Sun on Sunday -- formerly the News of the World -- had demanded people don't go to work on Wednesday with a headline "Cancel Wednesday!".
England fan Paul Seligson, a 61-year-old teacher, told The Sun he will heed their call to wear a waistcoat although with Britain currently in the midsst of a heatwave he could be in for an uncomfortable time.
"I think it's a great idea," said Seligson, who for the Sweden game on Saturday wore another traditional English apparel, a bowler hat.
"I may be going to the Croatia game as Henry VIII but I'll wear the waistcoat on top," he joked.
Seligson's friend Michael Dobres is also going but not dressed as a monarch but as one of his vassals, a beefeater.
"I'll be dressed as a beefeater but the waistcoat should complement it perfectly in honour of Gareth," he told The Sun.
"He appreciates the importance of an Englishman looking smart when he goes into battle and all fans should follow his lead."
Southgate lookalike, airline pilot Neil Rowe, who attended the quarter-final win over Sweden on Saturday after changing his mind over boycotting the tournament, told the BBC it had been tough wearing it in the heat of Samara for the quarter-final.
Nevertheless Rowe, a devoted England fan who has spent around £50,000 (56,600 euros, $66,500) to follow England over the past two decades, will wear his £65 Marks and Spencer waistcoat again on Wednesday.
Fans have demanded that Marks and Spencer reduce the price to a symbolic £19 and 66 pence -- representing the one previous year when England won the World Cup.