LONDON — British Prime Minister David Cameron said he was nervous but confident Scots would vote against leaving the United Kingdom when they vote in a referendum on independence next month.

With polls indicating support for a breakaway lagging behind backing for continuing the union, Cameron said he believed the "No" campaign's arguments were resonating with voters and accused the pro-independence camp of bullying opponents.

"I'm emotional and nervous. But only nervous because it matters so much," he said in an interview with the Scottish Daily Mail newspaper published on Saturday.

"I think the debate is going well. I think, the last few visits I've made, I've sensed that in the business community. The commentary has settled down, the argument is going better and I feel more confident. But it is a massive decision, so it's right to be both emotional and nervous."

This week Cameron, who has largely stayed on the sidelines of the debate because of his Conservative Party's unpopularity in Scotland, spent two days there ahead of the Sept. 18 referendum in which Scots will decide whether to end the 307-year-old union with England and Wales.

The possible economic impact of secession has been a focal point of the argument between the two camps and on Thursday Cameron said one million jobs could be put at risk if Scotland were to leave the United Kingdom.

"People can see the overwhelming opinion of businesses is that we are better off if the UK stays together," the prime minister told the Scottish Daily Mail.

"But I do hear a lot of businesses say they are frightened to speak because when they do the Scottish government behaves in a bullying and overbearing way."

A "poll of polls" on Aug. 15, which was based on an average of the last six polls and excluded undecided respondents, found support for a breakaway stood at 43 percent against 57 percent for remaining within Britain.

However a survey for the Scottish Daily Mail earlier this week indicated the gap had narrowed, with the "No" campaign enjoying just a six-point lead over supporters of independence, with many people still undecided.