And if parliament think he is bound by law to do this then they can take him to court to prove it.
They don't need to. He has already confirmed to the court he will seek the extension.
Why is this causing so much confusion?
The law says he must seek an extension.
He has written to thr court and confirmed he will do so.
End of.
If he changes his mind, then the court will appoint someone to do it instead, literally within hours.
There is nothing to see here. Seriously.