DHAKA: British prime minister David Cameron urged Scots on Thursday to stay in the United Kingdom during an unusual two-day visit to Scotland to counter a rise in support for secession in opinion polls and criticism of the anti-independence campaign.

Cameron has so far taken a low-profile role in the increasingly heated debate about independence that will be decided at a September 18 referendum, aware he has limited appeal in Scotland where his Conservative party is unpopular.

But as nationalists gain ground on pro-UK supporters in polls, more heavyweight politicians are joining the cross-party fight against independence, arguing the union of England, Scotland, Wales and Northern Ireland is stronger together.

A TNS survey this week found the gap between the two sides had narrowed to a new low of 9 percentage points from 22 points last September among Scots certain to vote, and 53 percent of voters described the anti-independence campaign as negative.

BDST: 2200 HRS, MAY 14, 2014