Three opinion polls ahead of the vote showed rising support for the Remain camp, however the overall picture is still one of an evenly split electorate. Campaigning resumed yesterday after a two-and-a-half day stoppage due to the horrific murder of MP Jo Cox.
Read more: Markets brace for referendum turmoil
Brent crude, the global benchmark, rose 1.9 per cent to $50.10 per barrel in mid-afternoon trading, having hit an intra-day high of $50.40. West Texas Intermediate, the US benchmark, also swelled 1.9 per cent to $48.90.
"Oil prices remain on a charge from their recent lows," Mike van Dulken, head of research at Accendo Markets, said.
Read more: Oil at $20 per barrel talk re-emerges
"The main driver is US dollar weakness as well as renewed hopes that a UK vote to stay in the EU will help maintain gradual global economic recovery and eventual rebalancing of the oil market."
The black stuff had slipped to a one-month low on Thursday after six consecutive days of losses. This came amid growing concern that the UK would vote Leave on 23 June as well as resurgent global growth fears.