UK Accepts 'Managed Divergence', 'Getting There', But Not On Fish: BBC

BBC Europe Editor Katya Adler tweets a long but potentially crucial thread on Brexit talks:

• Notes of careful optimism in EU off-record briefings .. Not just the public 'maybe, possibly, but let's see' of the European Commission President in front of the European Parliament this morning. EU sources saying U.K. has accepted the idea of 'managed divergence' in exchange for preferential access to single market. Ie if U.K. divergences from EU standards (which U.K. gov demands as its post #Brexit 'sovereign right') then EU has right to retaliate eg with tariffs.
• Obvs right to retaliate would go both ways eg if U.K. views EU businesses as having unfair advantage after Brussels changed standards. Still to be agreed: what mechanism to judge whether unfair advantage exists or not.. EU has accepted it can't take unilateral action.
• The above +more bilateral shifting means EU feels its priority in the deal is on way to being sorted ie protecting single market and European businesses in it even if UK gets tariff and quota-free access. U.K. principle of sovereignty - right to make own rules - protected too leading EU diplomat to declare "We're getting there." BUT not when it comes to fish .. Here it's not just about ongoing U.K.-EU differences but also tensions between EU coastal nations.
• France has famously been outspokenly tough on fish. Wants to protect French fishing rights in Channel. If it gets anything near what it wants, I'm told by EU insider, then EU wld have to compensate by giving up rights in other waters eg around Cornwall, also north of Scotland. Spain v concerned. Danish and Dutch too. They ask why they should lose fishing jobs to placate Macron .. These are just the complications intra-EU, never mind finding final fishing agreement with U.K.
• On EU side, guesses are that chief negotiator Barnier will -in the end- call the bluff of EU coastal nations. Along the lines of: If you don't compromise on fish, we'll have no deal at all - at far greater cost!.. This is for the coming hours/days, Im told.
• EU countries privately dismiss the pledge given by European Commission President to European Parliament that -even if a deal is reached - it won't enter force provisionally if no time left this year for EU Parliament to vote.
• "It's not in her gift to promise that" is reaction of a number of member states. EU law allows approval of deal by member states only- leaving out EU Parliament if necessary. EU countries' attitude is they'd refuse to enter even a short period of costly no deal if unnecessary
• Depending how many European Parliamentary committees want to scrutinise the deal IF it emerges in next days (and yes, it's still an 'if') then theoretically it might still be possible for MEPs to vote on it on 28th December, I've been told - even if it's not 'ideal'