Any references for that? Even if true how the hell is that relevant, Assange is wanted for questioning on a set of charges that are pretty serious and merit extradition to Sweden. The UK has a strong history of extradition to the US, including of UK citizens so lets not think Assange was 'safe' in the UK. Isn't the reality that Assange is a bit of a douche and just wants to avoid questioning on this topic and is throwing about FUD and pretending to be a martyr to deflect attention away from the allegations.
For a man who preaches openness about the world he sure likes to hide behind things.