GLASGOW, Scotland (Reuters) - 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.
Visiting Walcheren Barracks in Glasgow, Scotland's largest city, Cameron said he was "heartened" to see so many people find a voice in the debate over whether Scotland should end its 307-year tie to England and stressed the union was better together.
"We want Scotland to stay. We are all enriched by being together. Scotland puts the 'great' into Great Britain. Together we are a United Kingdom with a united future," Cameron said in a statement.
It is his second visit to Scotland this year and access to him was tightly controlled, with his office bypassing the usual system of issuing details of his trip in advance to the media.
Cameron received scathing criticism after his last trip to Scotland in February when he flew in for a few hours to visit an oil rig and lead a cabinet meeting in Aberdeen and left.
This did little to bolster the image of the Conservative party which holds only one of 59 Scottish seats in the UK parliament, prompting frequent jokes there are more giant pandas in Scotland - two at Edinburgh zoo - than Conservative MPs.
Aware of his status in Scotland, Cameron recently made it clear he would not quit as prime minister or Conservative leader if Scotland voted to break away, which was seen as a bid to deter Scots from voting for independence to punish him or his party.
Cameron is likely to face most of the blame if Scotland does leave the union as he approved the referendum in 2012 when there seemed no chance of a vote for independence.
First Minister Alex Salmond, head of the Scottish National Party (SNP) that won a landslide victory in the 2011 Scottish parliament elections, said Cameron had negligible support in Scotland and his party would never represent Scots.
Salmond is hoping that opinion polls this month showing the Conservatives have taken the lead over opposition Labour in Britain before a general election in May 2015 will persuade more voters that Scotland is better off on its own, run by its own elected government.
The rising popularity of the anti-EU UK Independence Party (UKIP) before next week's European elections could also play into Salmond's hands as he is adamant that an independent Scotland should be a member of the European Union.
With four months to go, both sides are ramping up their campaigns with Cameron expected to make more trips to Scotland.
(Writing by Belinda Goldsmith; Editing by Raissa Kasolowsky)