The chief architect of devolution today dismissed the 'offer' of more powers for Scotland in return for a No vote on September 18, as a 'desperate bribe' by the anti-independence parties.
Canon Kenyon Wright, who chaired the Scottish Constitutional Convention which laid the groundwork for the re-establishment of the Scottish Parliament in 1999, warned voters not to be taken in by parties that fought hard to keep a 'more powers' option off the referendum ballot paper.
He said: "David Cameron and his establishment colleagues could have done this long ago. Like many, I argued for a second question offering a middle way - which I saw not as devolution but as 'constitutionally secure autonomy within a reformed UK'. That door was slammed shut - but not by Scotland.
"So Messrs Cameron, Miliband and Clegg cannot be surprised if I now see independence as the only way left open, to give Scotland power over her own affairs that is both complete and secure. Their way offers neither."
Canon Wright, a retired Episcopalian clergyman, added: "The latest 'offer' of more powers from the unionist parties looks suspiciously like a rather desperate bribe - but it is not an answer to Scotland’s needs.
"The central issue at stake in the referendum is simple: Where should the ultimate power to make decisions that affect the lives of people in Scotland lie – at Westminster or in Scotland?
"As I should know, devolution - however 'max' it may be - is not the way, for two fundamental reasons. First, devolution is incomplete. It leaves vital areas directly under the control of Westminster. Take just one example of many - if the UK, as seems more and more likely, leaves the EU, Scotland will be dragged out too, at great cost.
"Second, devolution is insecure. The wording of today’s 'offer' is very revealing. It indicates that greater powers would be 'granted to Scotland'. Granted indeed? By whom?
"Scotland’s history is marked by Claims of Right, all of which rejected as a matter of Right the powers claimed by the 'Crown in Parliament' to decide for Scotland.
"Devolution is power, not as a right, but by gift – or more accurately by loan, since gifts can’t usually be taken back. Westminster would retain the permanent power to grant, alter, or rescind. Devolution leaves the UK as a whole fundamentally unreformed."
Blair Jenkins, Chief Executive of Yes Scotland, echoed Canon Wright's remarks. He said: "The fact that the anti-independence party leaders have come together at this late stage in the debate with this "offer" shows they are losing the campaign and the arguments.
"By making more vague offers of more powers for Scotland, the No parties have been forced onto our ground. However, as Canon Wright underlines, the only way to guarantee all the powers that Scotland wants and needs to become a better and fairer country is with a Yes vote."
The intervention from one of the architects of devolution follows a so-called 'declaration' by the three main Unionist parties of more powers for Scotland if there is a No vote in the independence referendum.
The declaration says: "We support a strong Scottish Parliament in a strong United Kingdom and we support the further strengthening of the parliament's powers."
"The Scottish Labour Party, the Scottish Conservative and Unionist Party and the Scottish Liberal Democrats have each produced our own visions of the new powers which the Scottish Parliament needs.
"We shall put those visions before the Scottish people at the next general election and all three parties guarantee to start delivering more powers for the Scottish Parliament as swiftly as possible in 2015.
"This commitment will deliver a stronger Scottish Parliament in a stronger United Kingdom."
However, a spokeswoman for First Minister Alex Salmond said "no-one in Scotland will be fooled by this Westminster-led rehash of vague promises and unspecified more powers in the event of a 'No' vote - the Tories have tried that before".
"David Cameron fought tooth and nail to keep a more powers option off the ballot paper, so how can anyone take him seriously now?"