The Prime Minister David Cameron wants the referendum on the renegotiation of Scotland's relationship with the rest of the UK to offer a simple yes or no choice on independence. But the Scottish National Party have said that, if they are convinced there is sufficient public support for it, in addition to a 'clean break' question, they would also like a second option on the table involving significant new powers for the Scottish Parliament but falling short of independence. This has been dubbed - 'devo max'. But what exactly is 'devo max'? What would it mean for the people of Scotland and what would be the consequences for the rest of the UK? Michael Buchanan tries to find out.
Producer Jane Beresford.