In this country Parliament is the sovereign legislature. Not the EU, not opinion polls, not the courts, not referenda, Parliament. We had an advisory referendum in 2016, which the 2015 Parliament decided to act upon and set the wheels in motion to leave the EU.
But then a strange thing happened. In September 2017 Theresa May decided she needed a stronger mandate to pursue her idea of Brexit, and held a General Election. She lost her majority, and the public, that’s the same people who had voted in the referendum, elected a House of Commons with widely differing views on what Brexit meant, or indeed, whether Brexit should happen at all. You could argue that the current House of Commons are broadly representative of what the public think, or at least, what we thought 2 years ago. Some are out-and-out Leavers, some are out-and-out Remainers, and some are more pragmatically trying to make the best of a bad job.
Opinion polls aren’t reliable because of their small sample size, but most say the public would now vote to Remain. Holding an election, because of the strange way our system works, wouldn’t necessarily tell us whether the polls are right, but a second referendum would. If the current deal, as amended by Parliament, was put before the public in a Deal/Remain choice, I would happily make it a legally binding vote.