Supporters of the "Britain Stronger IN Europe" group campaign in the lead up to the EU referendum, at Soho in London, Britain June 22, 2016. REUTERS/Neil Hall

LONDON (Reuters) - Investment bank J.P. Morgan said its analysis of recent opinion polls on Britain’s European Union membership referendum showed the “In” camp was narrowly ahead on Wednesday, a day before Britons go to the polls.

“On the basis of the data in hand, our clean-up process suggests a 2 percentage-point lead on average for ‘Remain’ in the polls published this week, with around 9 percent of the vote undecided,” J.P. Morgan economist Malcolm Barr said in an email.

“Our measure of the trend through the week-to-week noise now sits at a 0.6 percentage-point lead for ‘Remain’.”

Barr added that “subjectively”, he saw a roughly 45 percent chance Britain would leave the EU compared to the 25 percent chance priced into betting markets.