Scottish First Minister Alex Salmond has said he would "probably concede" to a third option being added to any independence referendum.
The option would be likely to offer greater powers for Scotland which would fall short of full independence.
But Mr Salmond said this did not mean the SNP was diluting its core aspiration for independence.
He said the outcome of the UK general election could present Scotland with some "pretty stark choices".
Mr Salmond's minority SNP government wants to hold an independence referendum next year, but the proposal is currently opposed by the majority of MSPs.
I am not frightened of another option on the ballot paper so long as that option is defined and meaningful, something people can understand and not some vague proposition
Alex Salmond Scottish first minister
Speaking on the BBC's Andrew Marr programme, Mr Salmond said his preferred option would be for a straight "yes or no" question on Scottish independence.
But he added: "I have also indicated that if it was necessary to obtain the parliamentary majority in the Scottish parliament to have a third defined option on the ballot paper, which could be done by a couple of questions or by preference voting, then I would be prepared to discuss that and probably be prepared to concede it, so long as independence for Scotland is on the ballot paper.
"People must have the opportunity to exercise their right of self determination. I am not frightened of another option on the ballot paper so long as that option is defined and meaningful, something people can understand and not some vague proposition."
Opinion polls suggest that independence is currently backed by a minority of Scots, but Mr Salmond said the outcome of the next general election could dramatically alter the political landscape.
He said that while it was possible the Conservatives would win a majority of Westminster seats, a hung parliament was a "very live possibility".
A "Scottish bloc" of 20 or more SNP MPs could have a "decisive influence" in a hung parliament and "tilt things in Scotland's direction," he predicted.
Mr Salmond also claimed it was clear that both Labour and the Conservatives wanted to make "swingeing" public expenditure cuts in Scotland.
"Therefore, overlying the constitutional debate is going to be a debate about the direction of the economy, the future of public services, the priorities that people have," he said.
The first minister pointed to the £100bn cost of replacing the UK's Trident submarine fleet, and asked whether it would be better to instead concentrate on "things that really matter like the health service and education system".
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