The campaign to keep Britain in the European Union has regained its lead in two opinion polls, giving a boost to Prime Minister David Cameron, who is battling to avoid a historic "Out" vote in the referendum.
Another survey also showed a change in momentum in favour of the "In" camp and Mr Cameron got the backing of a leading newspaper when the right-leaning Mail on Sunday urged its readers to vote to remain in the EU.
"We are now in the final week of the referendum campaign and the swing back towards the status quo appears to be in full force," Anthony Wells, a director with polling firm YouGov, said.
Financial markets around the world are on edge ahead of the June 23 referendum. A string of recent polls showing the "Out" camp in the lead pushed down on the value of sterling and helped wipe billions of pounds off stock markets.
A YouGov poll for the Sunday Times newspaper showed support for Britain staying in the EU had restored a narrow 44 to 43 percent lead over the "Out" campaign.
That poll was based on interviews conducted on Thursday and Friday, but the Sunday Times said the shift did not reflect the fatal attack on a British MP on Thursday which has led to the suspension of referendum campaigning.
Instead, the bounce in support for "In" was more a reflection of growing concerns among voters about the economic impact of a so-called Brexit, it said.
Another YouGov poll reported on Saturday but based on surveys conducted a bit earlier in the week -- on Wednesday and Thursday -- showed the lead of the "Out" campaign narrowing to two points.
A third poll on Saturday, by polling firm Survation for the Observer newspaper, gave the "In" campaign a three-point lead, reversing a similar lead for "Out" in a Survation poll published as recently as Thursday.
But a fourth poll, by Opinium for the Observer newspaper, showed the two camp were running neck and neck with 44 percent support each.
While the Mail on Sunday came out in support of "In," its rival The Sunday Times, which sells around half the number of copies as the Mail on Sunday, said it was backing the "Out" campaign.