Scotland is set to narrowly reject independence in a historic referendum in one week's time, a new poll says.

The survey by YouGov showed the pro-union "No" campaign ahead by four points on 52 percent support, compared to 48 percent who were in favour of independence, excluding respondents who picked "don't know".

The result was the first time the "No" campaign had gained support in a YouGov poll since early August, when surveys began to show the pro-independence side gaining a surge of support.

A Saturday poll by YouGov showing the pro-independence side ahead for the first time electrified the campaign, prompting British Prime Minister David Cameron to cancel a parliamentary debate and travel to Scotland with rival party leaders to campaign against independence.

The survey questioned 1,268 voters between Tuesday and Thursday.

Source: AFP