Council bosses have threatened to prosecute man for flying the St George's Cross flag that was branded "advertising".
Accountant Rob Swire was ordered to remove the 6ft x 4ft flag, which sports the Three Lions England crest, by town hall officials on Merseyside.
Sefton Council's Planning and Economic Regeneration Department deemed the patriotic symbol unauthorised advertising.
Mr Swire had raised the flag on a pole fitted to a tower above his first floor flat, which stands in a parade of shops at Hillside, Southport.
Council officials decided that it was an "advert" because it includes three lions in the middle of the St George's cross - in the style of the sports firm Umbro.
A letter from Sefton Council Planning and Economic Regeneration Department said: "It has come to our attention that an advertisement/flag is being displayed on your property.
"The advertisement is subject to regulation and I have been unable to trace any consent for its display. That being so the advertisement is unlawful.
"Under Section 224 of the Town and Country Planning Act 1990 it is an offence to display and advertisement other than in accordance with the regulations."
Mr Swire was given 14 days to remove the flag or face the threat of prosecution.
Mr Swire, 49 said: "I bought an official England flag to fly during the World Cup and just had not got around to taking it down.
"The letter from the council didn't even explain what this 'advert' was but I assume it's because the Three Lions logo is deemed to be some kind of trademark.
"It's ridiculous - I was only trying to be patriotic.
"It's a heavy handed approach from town hall jobsworths who don't have anything better to do."
A spokesman for Sefton Council said: "We received a complaint about the flag and we carried out an investigation.
"This is purely a planning matter because national rules state that this type of flag currently needs planning permission.
"Therefore, following a complaint, we were left with no choice but to ask that it be taken down."
However, Bob Peedle, a fellow of the Royal Society of St George, condemned the decision as "a great shame".
He said: "It's a great shame that the law prevents the flying of the St George's Cross in this way.
"Councils have also objected to the flag because it might incur racial hatred.
"Such restrictions are very upsetting to us patriots who are not interested in politics or advertising but simply proud to fly the England flag."
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