SCOTLAND will have to wait at least three years - until 2017 at the earliest - for the full implementation of enhanced powers to Holyrood, a UK Government minister has indicated.

The senior source, who is close to David Cameron, suggested the extra powers within the 2012 ­Scotland Act will have to be introduced first before any further changes can be implemented.

One key change is the setting up of a new Scottish rate of income tax. John Swinney, the Scottish Finance Secretary, is due to announce the level of the rate in his Budget next year but it will not come into effect until 2016.

The UK minister explained how the granting of more powers to Holyrood would be in the first Queen's Speech following the May 2015 General Election, which will set out the new government's legislative programme. There would then, he stressed, be an involved process of lengthy debates in the Houses of Commons and Lords.

This, he said, would be made more complicated by the parallel process of English votes for English laws, so-called Evel, in which Scottish MPs would be restricted on what UK legislation they could vote on.

The senior source also pointed out that on a practical level a new Revenue Scotland, set up to collect some of the new taxes devolved under the 2012 Act, would have to be significantly expanded to take on the role for Scotland currently undertaken by HMRC.

"We are fully committed to giving Scotland more powers as has been made clear, but it is not something that can happen overnight. It is complicated and will take time," explained the minister.

Had Scots voted Yes on ­September 18, the Scottish Government would have begun a complex set of negotiations with Whitehall with full independence envisaged to start from March 2016.

However, during the ­referendum campaign the Prime Minister stressed the process of introducing enhanced powers would begin "soon". And the vow of the three UK party leaders spoke of how a No vote would deliver "faster, safer, better change than separation".

Following the referendum result, the political process of delivering more powers for Scotland has already been hit by complications, with the different parties wanting varying levels of devolved income tax.

Secondly, the Lib-Con Coalition has made it clear the promise of more Scottish devolution is not contingent on that of more devolution for England but some Tories, such as Surrey MP Dominic Raab, believe it should be.

Gordon Brown, the former Labour leader, has branded Evel a "Tory trap" as it could be used to restrict Scottish MPs from voting on key financial issues, such as the annual Budget, which will continue to a major impact on Scotland regardless of enhanced devolution.

Ahead of a Commons debate on devolution later this month, the Kirkcaldy MP has collected nearly 100,000 signatures opposing Evel.

Furthermore, the SNP have insisted any attempt by Mr Cameron to link the Scottish and English devolution issues will enrage the Scottish public.

* The UK Government has rejected a call by Nicola Sturgeon to halt the introduction of universal credit in Scotland.

The Deputy First Minister had written to David Cameron demanding a delay while new powers for the Scottish Parliament are being considered. She claimed that bringing in the new universal credit, which will roll six existing benefits and tax credits for working-age people into a single payment, would make it harder to devolve housing benefit.