The British government plans to offer Scotland more financial autonomy in the coming days as polls predict a very close vote in the upcoming referendum on Scottish independence.

Chancellor George Osborne told BBC on Sunday that the government is finalizing plans to give Scotland "much greater" fiscal and tax autonomy and will unveil the proposals in the coming days.

He spoke after polls showed a tightening of the vote ahead of the landmark September 18 referendum on whether Scotland should become independent from Britain. The latest surveys show those who favor independence gaining ground despite British government warnings about possible pitfalls.

Osborne said the polls show how important every vote will be and reiterated that an independent Scotland would not be able to use the British pound.

He said Britain's three main political parties understand Scottish voters want more autonomy and that the new proposals would be substantive.

Scottish Deputy First Minister Nicola Sturgeon said the British government's "Better Together" campaign seemed to be "engulfed in panic" as the competition for votes tightens.

She said that if the British government was serious about giving Scotland more financial powers it would not have waited until two weeks before the referendum.

"There is no option of more powers short of independence on the ballot paper," she said. "There is no guarantee whatsoever that if Scotland votes 'No' we will get a single additional power for the Scottish Parliament."