So Theresa May is going to trigger Article 50 and dump the UK out of the EU buy the end of March 2019.
However, as all this is happening the electorate is changing due to basic demographics.
Each year about 500,000 people die, most of those of old age. In the referendum over 65s voted 60% - 40% in favour of Leave. So 300,000 Leave voters are dying every year while 200,000 Remain voters are dying. This may seem a bit macabre but that means Leave is losing around 100,000 a year of its majority, just through natural demographic changes.
This is only half of the story however because around 1,333,000 people a year reach the age of 18 and become eligible to vote. The youngest voters voted 75% - 25% in favour of Remain, which means the net Remain vote is increasing by around 667,000 each year. Add this to the net 100,000 reduction in the number of Leave voters in the over-65 category and the Leave majority is going down, just through demographic factors, by 767,000 a year.
767,000 over two years and 9 months is 2,109,000 votes which the Leave camp is losing relative to Remain over the period before the earliest date at which the UK might leave the EU arrives.
The Leave majority on 23rd June was 1,269,501.
That means that, through demographic processes alone, the Leave majority of 1,269,501 turns into a Remain majority of around 840,000 by 30 March 2019. Even accounting for different levels of turnout and not everyone turning out to vote this is still likely to result in a Remain majority.
Of course all this does not include the likelihood of Leave becoming more unpopular (as it has already done in Wales, as the principality has now become majority Remain supporting) due to other factors such as economic effects starting to bite, the government's obvious confusion and the efforts of groups such as Leavewatch monitoring the antics of the Brexiters. Even though the mainstream media has imposed an effective blackout on any news regarding the £350,000,000 a week that the Leave campaign says will not now materialise for the NHS, this message will start to get through to all but the most resistant Leave supporters.
The case against another referendum has never looked weaker.