Gary Lineker blamed "old age" as he apologised for shopping without a face mask.
The 59-year-old England legend was spotted walking the aisles of Marks and Spencer without covering his nose or mouth.
It comes after the Match of the Day presenter had previously urged others to follow the protocols on Twitter, report the Daily Star.
The former Tottenham striker tweeted in April: "How can there be any debate about whether we should be wearing a mask?
"Even if it's only a one per cent chance of making you safer. Even if it is only a one per cent chance of stopping you giving it to someone else. Even if it only saves one life then it has to be beneficial."
He then added in July: "Can't understand why anyone would object to wearing a mask.
"Painless gesture to ensure you don't spread the virus to others, and great for hiding bad breath."
And less than two weeks later, he posted: "Why would anyone object to wearing a mask in a shop? Not exactly a hardship. What a country of snowflakes we've become."
He also tweeted: "Wearing masks, of all things, is the most obvious thing we can do to help decrease the spread of the virus and the smallest of all the sacrifices.
"No brainer."
Lineker had even posted a photo to his Instagram page outside the same branch of Marks and Spencer in Barnes, south-west London, captioned: "I'm taking no chances."
A fellow shopper who saw Lineker browsing without wearing a face covering on Sunday said: "It's just hypocrisy on another level.
"He had even tweeted a photo of him wearing a mask recently in front of that same M&S store and told people to wear masks in supermarkets.
"If it was anyone else I wouldn't mind so much. But it's frustrating for someone who tries to take the moral high ground as much as he does."
Lineker tweeted on Monday: "In my old age I went into a store and forgot to put my mask on. Was wondering why people were giving me daggers. Realised after a couple of minutes and hastily put it on.
"Felt awful and embarrassed. Apologies to those present."
