michael barnier, the unity of the eu member states really being seen as a critical in the negotiating process. we heard earlier from the president of the european commission jean claude-yunker who expressed his sadness this day had to come. i m upset because leaving the european union is not a moment of but a moment of deep sadness. reporter: now, in the last few minutes or so we have seen the arrival of british prime minister theresa may. she is now expected to meet with