A second Scottish independence referendum will stand in a stark contrast to the EU referendum, Nicola Sturgeon promised MSPs on Tuesday (21 March).

The First Minister of Scotland made the claim as she urged Holyrood to back a so called Section 30 motion on Wednesday.

The SNP leader wants to hold another plebiscite on Scotland break away from the rest of the UK between autumn 2018 and spring 2019.

"Those of us who advocate independence have a responsibility to consider a range of issues in light of the changed circumstances brought about by Brexit, circumstances we did not choose to be in. And then present that information in a clear way," Sturgeon said.

"That is exactly what we will do and we will do so in good time to allow scrutiny and debate well in advance of a referendum that is at the earliest 18 months away. And by doing so we will allow people to make a genuinely informed choice between being taken down a hard Brexit path or becoming an independent country able to chart our own course."

She added: "That will be in stark contrast to the EU referendum: Not only was there no detail and no answer before that vote,that remains the case shamefully so nine months after that vote."

But UK Prime Minister Theresa May, who has the legal authority to call a referendum, has vowed to block a second ballot on Scottish independence, telling Sturgeon "now is not the time" for the vote as Brexit talks begin.

Scottish Conservative leader Ruth Davidson also said voters north of the border were "sick to death of the SNP's games".

"They don't want another referendum any time soon, just three years after the last one," the unionist told MSPs.

"But let's cut to the chase: the SNP's plan was not actually about trying to hold a fair, legal and decisive referendum.

"It was about a well-rehearsed game to put forward unworkable proposals, wait for Westminster politicians to point that out, then rush to any nearby microphone – angry face attached – to trot out the same old tired complaints.

"This bull-dozer approach is completely at odds with the way the 2014 referendum was held. The UK and Scottish governments worked together on proposals for a fair, legal and decisive referendum."

Scottish Conservatives, Liberal Democrats and Scottish Labour will vote against the Section 30 order motion on Wednesday. But the six-strong Scottish Greens will back Sturgeon, giving the First Minister the votes she needs to pressurise Westminster on the issue.

However, the Scottish Greens could break a 2016 Holyrood election manifesto pledge with the move. "If a new referendum is to happen, it should come about by the will of the people, and not be driven by calculations of party political advantage," the document said.

The latest opinion poll from Panelbase, of more than 1,000 Scottish voters between 13 and 17 March, found that 53% of respondents rejected splitting from the rest of the UK.