New powers are to be transferred to Holyrood in March that will allow 16 and 17-year-olds to vote in Scottish elections, the UK Government has confirmed.

An agreement has been reached between Holyrood and Westminster about the timetable for a Section 30 order - which will allow MSPs to legislate to lower the voting age for Scottish Parliament and Scottish local government elections.

Scottish Secretary Alistair Carmichael said that after last year's independence referendum, in which 16 and 17-year-olds were given a say, the case for lowering the voting age was "undeniable".

The move is the first stage of implementing the Smith Commission proposals on further devolution.

The Section 30 order is being used to ensure the voting age can be reduced to 16 in time for the next Scottish Parliament elections, in May 2016.

The order will be put before both Holyrood and both houses of the UK Parliament tomorrow, and will then go before the Privy Council - a body which advises the Queen - for its approval in March.

It is expected that draft legislation to implement the remaining Smith Commission proposals, which will give Holyrood new powers over income tax and welfare, will be unveiled by the UK Government on Thursday - ahead of the January 25 deadline.

Mr Carmichael said: "I'm delighted to confirm a timetable has been agreed for 16 and 17-year-olds to vote in future Scottish Parliament elections. I've always been a firm believer in votes at 16, with the sheer number of young people participating and voting in last year's referendum I believe the case has become undeniable.

"Today marks the next phase in our commitment to people in Scotland and the start of a landmark week for the future of our country. Later this week we will publish draft legislation ahead of Burns Night meeting our promise to bring new powers built to last for the Scottish Parliament."

Deputy First Minister John Swinney insisted Westminster must adhere to both the "letter and the spirit" of the Smith Commission when the draft legislation is revealed.

Mr Swinney said the publication of draft clauses to turn the recommendations into law must mark the beginning and not the end of a process to "empower" the Scottish Parliament.

The Deputy First Minister, who was one of the SNP's representatives on the commission, said: "Any proposals put forward this week must be the start of a process of devolving power and not the end.

"This week Westminster must demonstrate clearly that it will translate the proposals from Smith into legislation and ensure that the powers are transferred to Scotland fully in keeping with both the letter and the spirit of the Smith Commission and in a way which has the support of the people of Scotland."

Mr Swinney called for all parties to listen to what civic Scotland had to say on the draft legislation.

He argued: "The publication of these proposals creates the opportunity for people and organisations across Scotland to have the opportunity to shine a light on what is being offered.

"Whilst Smith did not recommend all the powers I would want the parliament to have, we will use what powers are made available, as far as possible, to increase equality, to tackle poverty and to grow the economy.

"And we will lead the debate to ensure the Scottish Parliament is equipped with the powers our people believe it should have to tackle the fundamental challenges in our country."

First Minister Nicola Sturgeon said: "It has long been this Government's policy to reduce the voting age to 16. The Scottish Government's decision to extend the vote to 16 and 17-year-olds in the referendum legislation is widely seen as an outstanding success and contributed to the unprecedented level of democratic engagement we witnessed.

"I am delighted that there is now cross-party support in the Scottish Parliament for extending the franchise to include 16 and 17-year-olds for Scottish Parliament and local government elections. I stressed the need for rapid action on this front when I met David Cameron in London before Christmas - and I am delighted we now have a deal."