As it happens, I know exactly where this lie started (or at least one version of it). Some blogger on the auto-industry posted a misleading comment that hard-brexiteer "journalist" Julia Hartley-Brewer tweeted a lie about. She didn't even stick to the original blogger's misleading comment; she took it even further and just made shit up. Now people are repeating her lie without checking. Given that she has a track-record of lying about Brexit; I don't have any problem suggesting those repeating her lies are doing just that... repeating lies.