Yes, it is disputed.

You appear to be saying that there are people who dispute the existence of the words of the legislation setting up the referendum, which specifically state that it is advisory. And you seem to imply that this is a rational view, and that you are willing to entertain it.

No one questions that the government stated that its fixed intention was to accept the outcome of this advisory referendum, and that this remains its intention. The court case has nothing whatsoever with that, it is purely about whether, under currently existing legislation, it has the ability to do that without the approval of Parliament.