EDINBURGH (Reuters) - Scotland s First Minister Nicola Sturgeon said that if Britain is leaving the European Union then single market and customs union membership were  the only sensible option , adding that now the negotiations would move on to a new tougher level.  Move to phase 2 of talks good - but devil is in the detail and things now get really tough. If Brexit is happening (wish it wasn t) staying in single market & customs union is only sensible option. And any special arrangements for NI must be available to other UK nations,  she said on Twitter. Earlier the European Commission and Britain agreed that Brexit talks can move on to the second phase of negotiations, which will focus on trade. 