Pray tell DMcG (The man who talks to lawyers) who is and who has been giving our negotiators - "instructions, guidance and support" - up to now:

The media? The opposition? the people? The Trades Unions? The CBI? Or has it been the Government?

Personally, without speaking to a lawyer, I believe that to-date it has been the Government - And that Government since the process has been in train has been a Conservative Government led by Theresa May.