The Scottish Parliament was set up by an act of Westminster and, as such, decisions on Scotland's constitutional future are reserved.
For example, independence, even if backed in a referendum set up at Holyrood, would still require consent from London. The Scotland Bill, currently going through the UK Parliament, is to devolve new tax and borrowing powers to Holyrood, as well as devolving control in several other areas.
Here, BBC news online Scotland outlines the constitutional policies of the SNP, Scottish Labour, the Scottish Conservatives, the Scottish Liberal Democrats and the Scottish Greens.
Referendum Bill in next parliament giving people in Scotland a chance to have their say over Scotland's future and independence.
New job creating powers and greater financial responsibility devolved.
Strengthen current Scotland Bill on more powers for Holyrood.
Devolution of Crown Estate - in particular seas and foreshores which are at the heart of our renewable energy future.
Ensure Scotland takes greater accountability for its spending priorities.
Take forward the recommendations of the Calman Commission.
Support increasing the borrowing powers set out in the Scotland Bill, in like with the recommendations of MSPs.
Support devolving capital borrowing powers earlier that set out in the Scotland Bill.
Support the provisions set out in the Scotland Bill on more tax, borrowing and other powers for Holyrood.
Support the provisions set out in the Scotland Bill on more tax, borrowing and other powers for Holyrood.
Maintain commitment to federalism across UK.
Back a renewed convention on Scottish devolution, with the public and civic organisations in the driving seat instead of politicians
Back a multi-option referendum with choices including the status quo, a stronger Scottish Parliament with powers defined through a participative process, and full independence.
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