* Scotland votes on independence Sept. 18
* Cameron campaigning for no vote
* Yes camp accuses opponents of scaremongering
LONDON, March 14 (Reuters) - British Prime Minister DavidCameron will urge Scots on Friday to heed warnings from the headof the Bank of England and business leaders over voting tobecome independent in a referendum in six months' time.
Cameron will tell the Scottish Conservative Party conferencein Edinburgh that the Sept. 18 referendum is a major life choiceand no decision should be made without being fully aware of theconsequences.
Business leaders have raised concerns about Scotland leavingthe United Kingdom due to uncertainties over currency, tax,regulatory regimes and European Union membership.
All three main UK political parties have ruled out sharingthe pound in a sterling zone, which is the Scottish government'spreferred currency option if voters back independence.
Cameron said the warnings were from non-partisan figures,with leaders of companies such as oil giants Shell andBP and financial services heavyweights Royal Bank ofScotland, Standard Life, and Barclays joining the debate in recent weeks.
His intervention comes after an opinion poll found supportfor independence was at its highest in six months. A Survationpoll found 39 percent of Scots planned to vote Yes forindependence compared to 48 percent No and 13 percent undecided.
"The idea that these are empty warnings and politicalscare-mongering is a myth - and we owe it to the people ofScotland to take that myth apart," Cameron will say, accordingto notes from the speech released in advance.
Scottish leader Alex Salmond argues that Scotland - with itsoff-shore oil reserves - could be a prosperous nation and thatindependence will give it the chance to raise and spend its ownmoney rather than being directed by a London-based government.
He has accused the pro-UK Better Together campaign ofscare-mongering about independence, dubbing it "Project Fear".
Although the separatists are still trailing in support,opinion polls have narrowed this year, prompting Britishofficials to warn over complacency leading up to the referendum.
Cameron last month stepped up the debate with a speech atthe cycling venue used for the 2012 London Olympics dubbed a"love-bombing" by commentators in which he declared to Scots:"We want you to stay".
On Friday, he will use sport again, with Scotland due tohost the Commonwealth Games in July, to stress the strength ofScotland staying with England, Wales and Northern Ireland,describing them as a "family of nations".
"We'll see the strength of that family again at theCommonwealth Games this summer," he will say.
"When the call went out for volunteers at Glasgow 2014, morethan a quarter of those who responded were from elsewhere in theUK ... because it's not 'over the border', it's not a foreigncountry, this is our home, and when any corner of these islandsneeds back up or support, the rest is there."