HOLYROOD does not have the power to declare Scotland independent and a second vote on the nation’s future is unlikely to take place until after the Scottish parliamentary elections in 2021, the House of Lords Library has indicated.

Its briefing paper on the parliamentary procedure to allow Holyrood to call another poll comes as Nicola Sturgeon prepares to set out the measures her Government intends to take "to progress the will" of the Scottish Parliament, which last month mandated her to seek the power from Westminster to hold another poll.

Prime Minister Theresa May has insisted "now is not the time" to stage a second referendum and the UK Government has made clear it will not even talk about the issue until after the Brexit process is completed.

MPs are set to consider shortly whether or not there should be a debate on a petition that says a second referendum on independence should not be considered.

It has now topped more than 220,000 votes, meaning it has crossed the 100,000 threshold, whereby the Commons Petitions Committee has to consider holding a debate on it.

The petition, which came about after the First Minister announced she intended to request another poll on Scotland’s future within the timescale of the autumn of 2018 and the spring of 2019, reads: “Another Scottish independence referendum should not be allowed to happen. We in Scotland are fed up of persecution by the SNP leader who is solely intent on getting independence at any cost. As a result, Scotland is suffering hugely.”

In its briefing paper on the so-called Section 30 Order, which would transfer the power to hold a referendum from London to Edinburgh, the House of Lords Library notes how, under the 1998 Scotland Act, matters relating to the constitution are reserved to Westminster.

It points out: “Paragraph 1(b) of schedule 5 is also of note in relation to the issue of independence. It states that ‘the Union of the Kingdoms of Scotland and England’ is a reserved matter, thereby meaning that the Scottish Parliament cannot declare Scotland independent as it does not have the legislative competence to do so.”

The paper explains how the Section 30 Order granted in 2013 had certain conditions attached to it by the UK Parliament, including the independence referendum should take place by December 31 2014 and there should only be one ballot paper with two choices.

It also explained the parliamentary process, which from the UK Government’s consultation to the actual vote took two years and eight months.

Given the UK Government has made clear it will not even discuss another independence referendum with the Scottish Government until after the Brexit “process” is completed, then, even if this is thought to end in March 2019, then a similar process would push holding a second vote beyond the May 2021 Holyrood election.

The timeline for the 2014 independence referendum was:

*Jan 10 2012: Michael Moore, the Scottish Secretary at the time, announced a consultation on the referendum process and Alex Salmond, the then First Minister, announced the poll would take place in autumn 2014;

*Oct 15 2012: David Cameron, the then Prime Minister, and Mr Salmond signed the Edinburgh Agreement, approving the method to enable the Scottish Parliament to hold a referendum based on a single yes/no question;

*Oct 22 2012: the Section 30 Order was laid before Westminster;

*Dec 5 2012: Holyrood approved the order;

*Jan 15/16 2013: the Houses of Commons and Lords debated and approved the order;

*Aug 7 2013: the Scottish Independence Referendum[Franchise] Bill was passed in the Scottish Parliament and received royal assent, setting the franchise for the poll;

*Dec 17 2013: the Scottish Independence Referendum Bill was passed in the Scottish Parliament and received royal assent, setting out the rules for the referendum;

*Sept 18 2014: the referendum was held and

*Sept 19 2014: the result was announced with 55.3 per cent voting No and 44.7 per cent voting Yes, meaning that Scotland remained part of the UK.