Constitution Secretary Derek Mackay has called on the public to give their views on a draft Bill on a second independence referendum.

Mr Mackay said the option of Scottish independence "must stay on the table" as he urged people to respond to the Scottish Government's consultation on the legislation, which closes on January 11.

The consultation, launched in October, proposes rules that would govern any future referendum, largely mirroring those that underpinned the vote in 2014 when Scotland rejected independence by 55% to 45%.

First Minister Nicola Sturgeon has insisted voters north of the border should be given the chance to consider the issue afresh after the European Union referendum which saw the UK as a whole vote for Brexit while a majority in Scotland wanted to remain.

Ms Sturgeon has published proposals aimed at protecting Scottish interests in Europe, which include options to allow Scotland to remain in the single market even if the rest of the UK leaves and the transfer of significant powers to Holyrood.

But she has also stressed the Scottish Parliament must be able to consider the option of an independence referendum ''if it becomes clear that it is the best or only way of safeguarding Scotland's interests''.

Mr Mackay said: "The EU referendum result is the biggest threat in modern times to our long-term economic well-being and leaving the EU could affect Scottish jobs, investment and standards of living.

"Scotland's Place in Europe, published last month, set out proposals to protect Scotland's place in, and relationship with, Europe, However a material constitutional change has occurred since 2014 and the option of independence must stay on the table.

"Any decision on holding a referendum is for the Scottish Parliament. Our intention is that the Bill is ready for introduction should the Scottish Government decide that a referendum on independence is the best or only way to protect Scotland's interests.

"It is important that any future referendum on independence would meet the gold standard in terms of fairness, transparency and propriety set by the one in 2014 - and I'd encourage anyone with an interest to give us their views before the consultation closes next week."

It follows a BMG poll for the Herald newspaper which found that when those who are unsure are excluded, 61.5% are against holding a fresh vote in 2017, compared to 38.5% who support it.

Excluding ''don't knows'', the poll put support for an independent Scotland at 45.5%, almost identical to the result in 2014.

Scottish Conservative constitution spokesman Adam Tomkins MSP said: "The SNP got all the feedback it needed in September 2014. The people of Scotland voted decisively to stay part of the UK.

"This attempt at a re-run from the nationalists is desperate, and risks causing even further uncertainty across the country for workers and businesses.

"Repeated polls have now shown a majority do not want a second vote on this. It's time Nicola Sturgeon respected that."

Scottish Labour's Europe spokesman Lewis Macdonald MSP said: "There should not be a second independence referendum and there will be absolutely no support from Labour for the SNP's reckless plan.

"Scottish Labour is very clear that we want the UK to retain access to the EU single market to protect jobs and the rights of workers in Scotland.

"But the most important single market to Scotland is the UK. The SNP's own figures confirm that remaining part of the UK single market is more important for Scotland's economy than even being in the EU.

"With power returning from Brussels, it is now clear that we need a People's Constitutional Convention and a new Act of Union to reform where power lies across the whole of our country, and to save the Union from the threat of the SNP and the Tories who risk pulling it apart."