The Scottish National Party today set out its plans for a referendum on Scottish independence.
A White Paper was launched by first minister Alex Salmond.
"It's time for the people to have their say on Scotland's future," he said.
The announcement was made on St Andrew's Day.
The SNP would hope the referendum is held next year.
But opposition parties, who hold a majority in the Scottish Parliament, have vowed to block the move.
The white paper sets out four possible scenarios for Scotland.
These are: no change in the present set-up; more devolution as recommended by the Calman Commission; a further degree of devolution; and full independence.
"It's time for the people to have their say on Scotland's future," Salmond said at the launch.
"The debate in Scottish politics is no longer between change or no change - it's about the kind of change we seek and the right of the people to choose their future in a free and fair referendum."
Running 176 pages, the White Paper entitled "Your Scotland, Your Voice" sets out various policy areas, such as management of the economy, agriculture and housing, and examines the implications for each under all four of the possible outcomes.
The SNP aims to publish a referendum Bill at the beginning of next year, with a plebiscite planned 12 months from now.
Dods Parliamentary Communications Ltd