The feeble reaction by the authorities came amid shocking scenes outside the Houses of Parliament earlier last weekend when officers decided to take no action against a man and a little girl waving the jihadi symbol.
Metropolitan Police chief Sir Bernard Hogan-Howe described the act as “not necessarily the worst thing in the world” while London mayor Mr Johnson today backed him saying “we live in a free country”.
But critics have compared the evil jihadi symbol to the Nazi swastika and are gobsmacked no action will be taken over those brazenly supporting the hated terrorist organisation.
Paul Nuttall, deputy leader of the UK Independence Party (Ukip), said: “If someone was walking around waving a swastika what would happen?
“The ISIS flag is just as bad and people should be arrested for waving it.”
Mr Nuttall, also MEP for the North West, said the decision not to prosecute was even more bewildering when you compare British authority’s actions towards the England’s St George’s flag.
He told Express.co.uk: “We seem to be embarrassed by the St George flag, which is a flag of peace, and there are often cases of people being told to take it down. But we are prepared to allow a flag flown that is a symbol of hate and intolerance. It’s bizarre.”
There has been a host of instances of the English national flag being banned over the years including a taxi driver in Devon being ordered to take one down from her cab in 2013 and an army veteran being told by a housing association to paint over a cross on his front door.
And earlier this year the London mayor came under fire himself for being too “frightened” to fly the red cross at a party he held for St George in the capital.
Aides for the mayor said at the time it was not a conscious decision but eyewitnesses were flabbergasted at the lack of a national flag.
While he seemed less keen to celebrate the English national symbol, Mr Johnson defended people’s right to wave the ISIS flag.
Speaking today to LBC, Mr Johnson said: “We live in a free country. You would have to have primary legislation to designate certain bits of iconography as being illegal.”
He also said he could not make operational decision on behalf of the Met Police who deemed last weekend’s actions at Westminster “within the law”.
Sunder Katwala, director of think-tank British Future, which looks at integration, said the police decision was difficult to understand.
And he also compared the jihadi symbol to a swastika, saying: “The ISIS flag has no place in Britain. Its meaning is to glorify murder, terrorism and fascism.
“There must be a reasonable case that the police already have the powers to remove it if it is being flaunted provocatively, just as they would a nazi swastika.”