Jeremy Corbyn has repeatedly confounded his critics and demonstrated that he is a potential prime minister since, against all the odds, he became leader of Britain's Labour Party in 2015.
His prospects in the 2017 Westminster general election were initially dismissed but he won the key arguments against Theresa May, left the UK totally unexpectedly with a hung parliament and gained Labour's biggest increase in its share of the vote since 1945.
Mr Corbyn has since gone on to further strengthen his position, and take full control of almost all aspects of his party, but doubts remain over his attitude towards arguably the most vital issue he faces, Brexit.
He officially campaigned in favour of remaining in the EU, but the lack of enthusiasm he displayed during the 2016 referendum was unmistakable and was widely believed to be a key factor in the decision by many ordinary Labour supporters to sway towards the leave side which ultimately won a narrow victory in England and Wales but lost by a clear margin in Scotland and Northern Ireland.
Mr Corbyn has taken a low key approach to the shambolic efforts by Theresa May and the British government to negotiate an exit from the EU which will inevitably have disastrous consequences along the Irish border.
It is possible that he is playing a long game, and anticipates with considerable justification that Brexit may lead to end of the union and eventually to new agreed arrangements in Ireland, but he is still taking major risks along the way.
He is well aware that the wording put to the electorate in 2016 ignored the enormous divorce bill later handed to the UK, failed to ask basic questions about
the EU's single market and customs union and allowed emotions to be influenced by entirely false claims over immigration and the National Health Service.
Mr Corbyn will also know that details are steadily mounting about the way the Vote Leave group blatantly exceeded legal spending limits, with further significant evidence emerging over the weekend.
It is entirely reasonable to propose as a result that a second referendum is held on the final deal with the EU, but Mr Corbyn on Friday took the extreme step of sacking his well-regarded Northern Ireland shadow secretary of state Owen Smith for making just such a suggestion.
Brexit will have deplorable consequences in all parts of Ireland, and across Europe, as well as causing enormous damage to community relations north of the border and undermining the central provisions of the 1998 Good Friday Agreement.
Mr Corbyn should certainly reconsider his dismissal of Mr Smith but more importantly should also review his overall attitude towards the severe consequences which Brexit will bring to Ireland north and south.
