56 hours until the polls open with a leader is campaigning for every single one of your votes, but what is really going on behind the scenes? welcome to newsnight, for your nightly interviews and insight. and we will bring both to you on the week when you decide who s going to run our country for the next five years. tonight, we have the man who compiles the exit poll which you will see at 10pm this thursday on the bbc one election programme, professor sirjohn curtice. that should give you us, we hope the first accurate forecast of the election result. we also we have harriet harman, former labour minister, former labour deputy leader and an mp for over a0 years, standing down this time. and we have sir craig oliver, former director of communications for prime minister david cameron. welcome. and nick is here as always. cards on the table, i m after numbers, sir craig oliver, what would be a best and worst case scenario for the conservatives politically this thursday? the