A fresh poll has shown the campaign to leave the European Union has a two-point lead over Remain, down from a seven-point lead last week.
It comes as Brits prepare to vote on Britain's membership to the 60-year old political and economic union tomorrow.
Market researcher TNS' online poll conducted between 16 to 22 June showed 44 per cent of respondents would plump for Leave, while 41 per cent would vote Remain and 16 per cent were undecided or didn't intend to vote.
"It should be noted that in the Scottish independence referendum and the 1995 Quebec independence referendum there was a late swing to the status quo and it is possible that the same will happen here," Luke Taylor, head of social and political attitudes at TNS UK said in a statement.
"Clearly, with a race as close as this, the turnout level among different demographic groups will be critical in determining the result."
It comes after a separate online poll by Opinium conducted between 20 to 22 June showed support for Leave increased by one percentage point to 45 per cent, while Remain stayed at 44 per cent.
Meanwhile, bookies William Hill and Ladbrokes said that their latest odds show the Remain camp is the firm favourite to win. The former's odds show an 81 per cent chance of a Remain vote, while the latter's posit a 76 per cent chance of Remain.