As @Dammit says, they can talk all they like, but until the British Government formally notifies them of their intention to leave under the terms of Article 50, they can't force the issue.
It hasn't, but I'm sure there's a full understanding of what is required. For example, I can't phone up Jean-Claude Juncker and tell him 'on behalf of the UK, I hereby notify you that we've approved the trigger on article 50.'
As @Dammit says, they can talk all they like, but until the British Government formally notifies them of their intention to leave under the terms of Article 50, they can't force the issue.