Boris Johnson said today that controversial adverts and leaflets being distributed in parts of the capital encouraging illegal immigrants to leave voluntarily could be worded "friendlier".
"Frankly the language could be friendlier...It's a fine point. But I think it's absolutely right to tell people to obey the law", the London Mayor said.
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Transport for London is not happy that its branding has been used.
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Look closely at this collection of images by photographer Jim Grover and you'll notice there's something missing.