Two polls show voters are still closely divided over whether to end Britain's European Union membership, a day after another survey put the 'Leave' campaign 10 points ahead.
The results underline the contradictory polling less than two weeks before the referendum.
The pound weakened by as much as 1.2 percent against the US dollar immediately after an ORB poll for The Independent newspaper, showing a sharp swing toward a vote for Britain to exit the EU, was published on Friday evening.
Betting odds on Brexit also shortened after the survey, conducted on June 8 and 9, putting the 'Leave' camp 10 points ahead of 'Remain' -- the latest in a run of polls to show rising support for a British exit from the EU.
But two surveys published on Saturday showed divergent results with one giving a two-point lead to supporters of Britain's EU membership and a second poll showing those in favour of Brexit were one point ahead.
Britons will vote in a June 23 referendum on whether to leave the world's largest free trade area.
An Opinium poll for The Observer newspaper, conducted between June 7 and 10, suggested 44 percent of Britons back continued membership of the bloc with 42 percent against and 13 percent undecided.
But a YouGov poll for The Sunday Times showed support for Brexit on 43 percent with those who wish to remain part of the 28-member trading bloc on 42 percent, a reversal on the previous survey released on Monday.
On Saturday, bookmaker Betfair cut the odds of a vote to stay, after the ORB poll, giving a probability of 70 percent, down from 78 percent earlier this week.
Bookmaker Ladbrokes said the ORB poll had caused it to shorten its odds on Brexit to 9/4 from 11/4 previously.