Thanks for the replies. I did read them when you posted them but thought I'd give an update.
We haven't submitted an application yet and it may not be a problem getting permission from his dad, as it's what my son wants.
Unfortunately I was married to him.
He only sees his dad about 3 times a year as we live 250 miles apart and he doesn't make the effort to see him. I just wanted to be prepared in case it's an issue.
I read on another post that the Hague convention states that a 16/17 year old can decide themselves. So
I'm hoping that, as this is the law in my sons country of origin (England) that the Australian Immigration will except that.
I have tried to find a definitive answer by calling the Australian embassy in London but the customer advisor didn't know and advised me to ask a solicitor!?
I also tried citizens advise, a family solicitor offering free initial consultations for £120 (work that out?) and a couple of other free law advisors none of whom knew the answer.
So in an attempt to get a definitive answer I have written to the Australian embassy.
I will update the post when I get a reply.
Fingers crossed