As the referendum apparently had Royal Assent rather than just being invoked by the Government in power then the result has to be legally binding. I think Cameron shot himself in the foot there as it also means any legal challenge will fail. Not that I'm unhappy with the result. I voted to come out in 1975 and did so again this year.
I'm like @Big Brian, I knew what would transpire and did not agree with it then nor do I agree with it now. I firmly believe will are better off out of it.
BTW I remember being told here even informal talks cannot take place until A50 was invoked which I did agree with but consider this.
"Yesterday, Trade Secretary Sajid Javid flew to Delhi to start talks towards a trade deal with India. That is something we are forbidden from signing individually as a member of the EU – and yet the EU has failed on its own account to establish a trade deal with India, one of the fastest-growing economies in the world."
Sourcehttp://www.express.co.uk/comment/exp...t-Leave-voters
No doubt it will be happening with serveral other Commonwealth countries too.