It isn't easy to understand why some British Ministers are still so optimistic about Brexit. While the UK's Prime Minister triggers Article 50 later this month, the Irish republican party's leader says that "We must defend the democratic mandate of the people to remain in the EU". That's why Northern Ireland should hold a referendum on leaving the United Kingdom and joining the Republic of Ireland. In addition, as it is already known, a decision on calling a new Scottish independence referendum could be made within weeks: the first minister of Scotland, Nicola Sturgeon, recently said that plans to take the UK out of the EU's Single market have brought a second Scottish independence referendum "undoubtedly" closer.
Actually, it seems that the British Government is now on an unpleasantly difficult situation: on the one hand, Mrs. May says that British people would have truly left the EU when they would be in control of their own laws. On the other hand, she is still looking for the "Greatest possible access" to EU's Single market after leaving it.
According to an article published in "The Economist" on March 4th, 2017, The European Court of Justice will probably control any transitional arrangement which will be made between post-Brexit UK and EU. If the UK were to need trading relationships with the EU, it wouldn't be free from the shackles of the Luxembourg's Court of Justice.
Since the 1960s European Court of Justice have been supervising any trade deal signed by the EU. And all non-EU countries that seek close access to the EU's Single Market, such as Switzerland, Iceland and Norway, have been following the Luxembourg's rules.
As a result, notwithstanding the country has voted to leave the EU, Britain will not reach the aim to take the UK out of the European Court of Justice. Moreover, Scotland and Northern Ireland will try to leave the UK, and refugees and immigrates will be probably allowed to remain in Britain. It isn't easy to understand why someone is optimistic about Brexit.