They have to debate it, but they don't have to do it. It is a joke in some ways as we have only had above a 75% turnout once in many decades and that was in Scotland for the independance referendum. It has been calculated to ensure that no referendum could ever be successful, and then you have to ask what happens if you get less than 75% turnout in a general election. It is no news that there are big divides in the UK. There has always been a North/South divide in England. The heavy industries were all in the north and at the end of the last century they were decimated. Most of the wealth is in London and the South East with little in the North other than a little in the big cities. There are many places in the north with no investment and in the peoples eyes no future. It is the same in Wales, and many felt they had little to lose. In Scotland the SNP divided the country with their referendum. It is inexplicable that they want to seperate from the rest of the UK with their own strong devolved parliament, but wish to stay in the EU where they have no control over the laws passed, but old hatreds die hard in some people. In Scotland most of the heavy industry was decimated as well, and it was mostly those with no hope who felt they had nothing to lose who voted for independance. The vote was as much about frustration with our own politicians, they are a pretty mediocre bunch, as it was about the EU.
For me personally there could be no good result, if we stayed the problems in the EU would continue to build and in a few years there would be big problems for everybody, if we leave we have big problems now. In an ideal world the EU would have realised the problems, made the necessary reformations and dealt with them. I hope that now the necessary reforms will come for those of you in the EU, but I suspect that personalities, ideals and power struggles will get in the way as always. It is interesting that one of the the first reactions from the EU was 'We need to make it more difficult to leave' rather than 'we need to make people want to stay,' that says a lot about the people in charge of the EU. I am sure that the French in particular look forward to giving the UK a very hard time, I suspect their president is very worried about the consequences for him and we will be a handy scapegoat.
One thing that greatly annoyed me was when the official campaign decided to make immigration an issue, it never came into my considerations, there will always be a need for some immigration. There was a small minority who this was an issue for and some were easily persuaded it was an issue. Many who voted to leave had also voted to join in 1975, the EU quite simply hadn't met their expectations and neither had our politicians. I think it will be interesting to see what the vote is in the next general election and how many choose to vote.