Scotland’s nationalists suffered a second straight setback in the polls after YouGov Plc showed them trailing less than a week after overtaking the anti-independence campaign for the first time.

The survey for the Times and Sun newspapers put support for breaking away from the U.K. at 48 percent versus 52 percent backing for the status quo when excluding undecided voters, YouGov said on its website. That shows a three percentage-point increase for the No side and the same decline for the Yes side compared with the company’s last poll, for the Sunday Times.

Scottish residents vote in a referendum in less than a week on Sept. 18. The nationalists are seeking to regain momentum after a series of blows since Sept.10, coinciding with campaign trips to Scotland by Prime Minister David Cameron and other major U.K. party leaders in a bid to avert a Yes vote.

“One can look at this two ways,” YouGov analyst Anthony Wells said on his blog. “Perhaps the Scottish people recoiled a bit from the risk when it began looking like it would really happen. An alternative is that it’s just margin of error.”

David Fuller's view

Presumably the tension and suspense will persist until we have the election result, which is mostly a matter of whether or not a sufficient number of Labour supporters switch sides to ensure a No vote.  I would pay more attention to the betting shops which are usually more accurate.  They clearly favour a No vote: U.K. Bookies Are Betting Against Scottish Independence.