More in Scotland unsure how they will vote on independence referendum 4 (UPI) -- Only one in four adults in Scotland say the country should seek complete independence, a poll released Wednesday said That's the lowest level since it began polling on the issue in 2007, the market research firm TNS-BMRB said. The company's last poll in February found 33 percent supporting independence and 39 percent did so immediately after last year's elections, when the Scottish National Party won an outright majority in the legislative assembly. The referendum, backed by the SNP, is scheduled to be held next year. The latest survey found the share of respondents saying they are definitely voting against independence dipped slightly from 52 percent in February to 47 percent. The percentage saying they do not know how they will vote jumped from 15 percent to 28 percent. Tim Costley of TNS Scotland said the increase in "don't knows" could be significant as the campaign plays out. "The surge in the number of those who have not decided how to vote may have arisen because both campaigns have succeeded in giving rise to doubts among some who have previously backed the other side, without generating positive support for their positions," Costley said. With so many undecided, there is still all to play for. Scotland, like Northern Ireland and Wales, has a devolved government. Britain remains responsible for defense, foreign policy and taxation. TNS interviewed 1,017 adults in person between Aug. 21 and Aug. 27.