If, as Mrs May and Downing Street suggest, it remains her intention to signal on June 19 that Britain will leave the European Union and the single market and end free movement, there is a substantial body of opinion in political circles and the civil service that believes that when it comes to presenting the detailed bills to Parliament for Brexit implementation, she may find it hard to achieve a majority.
David Davies, the United Kingdom politician in charge of the negotiations, is getting all pally with his opposites on the EU's side of the table.
But the other 27 members of the European Union combined have about five times the economic might of Britain.
Amid doubts over the strength of Britain's diplomatic position, Brexit Secretary David Davis will begin negotiations with his European Union counterparts today in Brussels.
"Both sides will also discuss the structure of the negotiations and the issues that need to be addressed over the coming months".
- June 2019: European Parliament elections will take place without the UK.
"Effectively that's what we are potentially saying we might do".
"Our view is that withdrawal agreement and terms of the future relationship must be agreed alongside each other", said the spokesman.
"We believe that the withdrawal process can not be concluded without the future relationship also being taken into account".
The LCCI boss also called for "vital" clarity on the status of European Union workers with around 600,000 jobs in the capital held by EU-born workers, as well as protection for lower-skilled workers, "not just the cream at the top". "But the withdrawal and future are intimately linked".
Working groups will be set up to focus on three key areas - the status of EU citizens living in Britain and British citizens living in the EU; the divorce bill for Britain; and the future of the Northern Irish border with EU member Ireland.
Wu Xiaohui steps aside as Anbang chairman
According to Anbang, Wu's duties would be managed by other senior executives, and its business was operating normally. Caijing didn't immediately answer calls and emails requesting comment before regular business hours in Beijing .
But even though the complicated discussions haven't kicked off yet, we're sure they will soon: so we thought we'd put together a handy guide to the words and phrases you're going to be hearing over and over (and over) again in the next few years. Agreeing to pay a "Brexit bill" may be more inflammatory.
The shock outcome of the June 8 election saw PM Theresa May lose her parliamentary majority, sparking speculation the Tories may be forced to soften their hard-line Brexit stance.
Mr Barnier's insistence on sticking to the EU's priorities for the negotiations comes after Mr Davis appeared to soften his stance on the schedule for the talks.
Brussels has been insistent that a new trade deal can not be discussed until after Britain has left the existing one.
May has yet to change tack formally and doing so would risk infuriating euroskeptics in her Tory party who might still prove strong enough to scupper a deal or to topple her as leader if they believe she's backsliding.
"To threaten to jump off a cliff rather than to be pushed is not a viable negotiating strategy", he said.
The EU has made its opening position clear.
We now know that at precisely 11:00 BST on Monday morning, nearly exactly a year after the Brexit referendum, the all important exit negotiations will begin.
Davis and Barnier will hold a press conference later on Monday. She will not take part in day-to-day negotiations but is expected to set Britain's approach and have the final say on any compromises or concessions.
And the source told the BBC that it was understood the talks would broadly follow the EU's preferred sequence, dealing with issues of citizens' rights and a framework for calculating outstanding financial liabilities before moving on, possibly later in the year, to deal with the UK's future relationship with the EU.