Results from the latest surveys suggest that exactly 50 per cent support Brexit and 50 per cent would like the UK to remain in the bloc.
Individually, three of the six polls give Brexit a lead, while three give Remain the lead.
The most recent surveys, carried out online and published in The Observer and The Sunday Times, show a 51:49 and 49:51 split respectively, a knife-edge difference that highlights the difficulty in predicting the final outcome.