The decision of the Parliament of Scotland to ratify the Treaty of Union in 1707 was not unanimous and, from that time, individuals and organisations have advocated the reinstatement of a Scottish Parliament. Some have argued for devolution – a Scottish Parliament within the United Kingdom – while others have advocated complete independence. The people of Scotland first got the opportunity to vote in a referendum on proposals for devolution in 1979 and, although a majority of those voting voted 'Yes', the referendum legislation also required 40% of the electorate to vote 'Yes' for the plans to be enacted and this was not achieved. A second referendum opportunity in 1997, this time on a strong proposal, resulted in an overwhelming 'Yes' victory, leading to the Scotland Act 1998 being passed and the Scottish Parliament being established in 1999. Since then, additional powers have been devolved, and the Calman Commission is considering whether further powers should be transferred.