The plot thickens

So my old boss from my time in Brussels, Michel Barnier, has been appointed as the European Commission's Brexit negotiator.  The Guardian reports:

A veteran French politician and experienced Brussels insider who has repeatedly clashed with the City of London over financial services reforms is to lead talks on Britain’s exit from the EU.

The president of the European commission, Jean-Claude Juncker, said he had wanted an experienced politician for an “important and challenging job” as he announced the appointment of Michel Barnier, a former EU commissioner. Barnier would “help us develop a new partnership with the UK”, he said.

A member of France’s centre-right Les Républicains (formerly UMP) party, Barnier, a former French cabinet minister, will take up his post on 1 October. He said in a tweet he was “honoured to be entrusted” with such a demanding task. The appointment will be viewed with some apprehension in London.

All very well, but a quick glance at Article 50 of the Lisbon Treaty suggests that it is the European Council, rather than the European Commission, which is mainly responsible for the negotiations.  Possibility of a turf war between Tusk and Juncker?