As Brexit talks get ever more detailed and intense, Shaun Connolly, Press Association political correspondent explains the jargon and looks at the next steps

PRIME Minister Theresa May is battling to break the deadlock over the Irish border after a proposed deal collapsed on Monday, with the clock ticking ahead of a crunch summit on December 14.

The EU insists that trade talks can begin only after “sufficient progress” has been made on the three key divorce issues of citizens’ rights, the Irish border and the UK’s financial settlement.

And Dublin has warned that unless the UK provides cast-iron guarantees that the border will remain open, it will not allow Brexit negotiations moving on to the second phase – including trade talks – before the end of the year.

Northern Ireland’s Democratic Unionists – who prop up the Government in Parliament – have insisted they will not sign up to a proposal for Northern Ireland to remain in “regulatory alignment” with the Republic once Britain has left the EU.

Meanwhile Dublin has demanded assurances from the UK that there would not be any “regulatory divergence” between Northern Ireland and the Republic after Brexit.

What’s the difference between “continued regulatory alignment” and “regulatory divergence”?

THE word “alignment” offers a more flexible ambiguity to the sticky issue of the Irish border, which would have given London and Dublin more wriggle room to sell the idea of “frictionless” trade to their respective audiences.

It adds a looser, more EU-style fluidity to the concept of avoiding a hard border after withdrawal as “regulatory convergence” implies a stricter regime when it comes to standards and practices on both sides of the dividing line. And “regulatory divergence” suggests a clear break in some areas.

But even the “alignment” level of ambiguity was considered too strong by the DUP for them to accept, so it’s back to the dictionary to find a fresh form of words as the Irish Government says it will give Downing Street some space to deal with “presentational” problems.

How does phase two of talks differ from phase one?

FOR Remainers hoping that Brexit was just a phase, the bad news is that it is in fact two phases – and the first one was meant to be the relatively easy part.

Phase one concentrates on legacy “divorce” issues, such as the exit bill, the rights of British citizens living in the EU and those of EU nationals living here, as well as the Irish border. Phase two is intended to hammer out a post-Brexit trade agreement between the UK and the EU27, but bloc leaders will only sign off on opening the second section of talks if they deem “sufficient progress” has been made on legacy negotiations at a summit in Brussels next week.

What is sufficient progress?

WHATEVER the EU insists upon, it would appear, given the sudden eagerness of London to finally wrap up phase one as exemplified by the apparent acceptance that the Brexit bill will be up to £50bn, rather than the £18bn initially indicated by Downing Street.

Some sort of role for the European Court of Justice on citizens’ rights has also been talked of, along with the wordplay surrounding the Irish border issue.

So what are the key dates coming up?

DECEMBER 14 and 15. A scheduled two-day European Council summit offers a new opportunity for the EU27 leaders to decide whether talks can move on to trade. Failure to do so at this stage would mean crisis for Theresa May, with escalating calls for her to prepare to quit the EU without a deal. Figures in the City have warned that firms will start moving staff and functions out of the UK if it is not clear by Christmas what transitional arrangements will be in place to avoid a cliff-edge Brexit.

What is the schedule for early next year?

IF talks are proceeding to plan, negotiators can be expected to be getting into the nitty-gritty on how future trade relations will work while ironing out final details of the divorce deal during the winter and spring.

On March 22 and 23 there is a European Council summit in Brussels. If talks have not moved on to the second phase by then, the process will be in serious crisis, with time running out for any discussion of trade and companies across the UK forced to plan for the possibility that there will be no deal. Mrs May will come under pressure to pull out of talks. In May, English local government elections will provide the Prime Minister with her first widespread electoral test since the disastrous snap election of June 8, 2017.

Michel Barnier hopes to be able to conclude withdrawal negotiations around this point in order to allow time for them to be ratified before the end of the two-year Article 50 deadline on March 29, 2019. On this date, the UK ceases to be a member of the EU and is no longer subject to its treaties, whether or not a withdrawal agreement has been reached. Because the exact moment of exit is midnight Brussels time, the UK is due to leave at 11pm on March 29.