A professor in the north believes that if Britain exits the EU - people travelling from the south will need passports to enter the six counties.
Opinion polls over the weekend suggest the leave side is slightly ahead in the forthcoming in out referendum which takes place on the 23rd of June.
The deadline to register to vote is midnight tonight.
Queens Law Professor Dammar Schiek says it's the EU who will decide how our border with the North is controlled, if the UK opts to leave.
However she says there will be at least two years of negotiations before border checkpoints are put in place:
