Nicola Sturgeon: there may well be a case for a second Brexit referendum

“I think there may well be an argument for that,” she told a conference in Crieff yesterday.

Read more: SNP by-election victory in Labour heartland signals power shift in Glasgow

Waiting to judge the final deal would appear to rule out an independence referendum within the two-year Article 50 withdrawal process, despite Alex Salmond and others in the SNP arguing for a second vote well before 2019.

UK LibDem leader Tim Farron has also called for a second Brexit referendum, including an option of complete rejection of the June 23 vote.

Ms Sturgeon said the details emerging so far from the UK government were "deeply troubling" as they suggested “exit not just from the European Union but the single market".

She added: “I think there is a big job of work to be done at this stage to try and steer that in a different direction. I don't underestimate how difficult that is going to be."

But when then LibDem Scottish Secretary Michael Moore suggested a second referendum to ratify independence in 2011, Mr Salmond dismissed it out of hand.

His spokesman accused Mr Moore of "wittering and irrelevant nonsense".

Read more: SNP by-election victory in Labour heartland signals power shift in Glasgow

Earlier, Ms Sturgeon said she would stand “full square” with any company that boycotts the UK government plan to make employers report their foreign workforce numbers, despite a new poll showing half of Scots and almost half of SNP supporters are in favour of disclosure.

She attacked the proposal, revealed by Home Secretary Amber Rudd at the Tory conference, as “disgraceful and disgusting” and said her government “would have nothing to do with it.”

Under the Home Office plan, firms could be forced to publish the proportion of “international” staff they employ, effectively naming and shaming those with the fewest British workers.

At First Minister’s Questions, Ms Sturgeon condemned the “xenophobic rhetoric” of this week’s conference and said Scottish Tory leader Ruth Davidson should be “ashamed” of it.

Asked by Green MSP Ross Greer if she would support businesses who refused to comply with the “sinister” and “disgusting” proposal on foreign workers, Ms Sturgeon said: “I would absolutely stand full square beside any company that refused to comply with any request to publish details of foreign workers.

“What I found particularly offensive was the idea that companies would be named and shamed for the foreign workers they employed, as if there was something shameful about employing workers from other countries. It is absolutely disgraceful.”

Read more: SNP by-election victory in Labour heartland signals power shift in Glasgow

The First Minister said Ms Rudd had tried to “row back from the proposal” after business leaders and others attacked it, and said the Tories now needed to rule it out.

However a YouGov survey of almost 6000 people showed widespread public support for the idea, with 59 per cent of people in favour of reporting a worker breakdown.

Backing was strongest among Ukip (86 per cent) and Tory (73 per cent) supporters, but 46 per cent of SNP supporters also said they approved, with the same number disapproving.

The same poll also asked if a British worker should be prioritised over a foreign worker when two equally matched candidates applied for a job.

Across the UK, 60 per cent of people said the British worker should be prioritised, compared to 29 per cent who said there should be equal treatment

In Scotland, 54 per cent would prioritise the British worker, and 36 per cent would not.

Among SNP supporters, 53 per cent said they supported prioritising the British workers, compared to 29 per cent who said they did not.

Ms Davidson reminded MSPs she had taken a different tack in her conference speech, insisting her party must stay outward-looking and welcoming.

She said: “My position is that people from the EU and elsewhere are welcome here and that this is their home, and that we should retain the closest possible trading relationship with our European friends and neighbours while expanding trade abroad, but that we should also face up to the realities ahead of us, mitigate risks and take advantage of opportunities.”

Ms Sturgeon welcomed the remarks but added: “Unfortunately, the difference between her and me is that she wants control over immigration to stay in the hands of the xenophobes, whereas I want it to come into the hands of this Parliament, so that we can put those sentiments into practice.”

She said Theresa May's deadline of triggering Article 50 by the end of March 2017 was "driven more by the Prime Minister's desire to appease the Tory Eurosceptics than it is by any rational consideration of what is in the best interests of the country" and thus “deeply irresponsible”.

The First Minister’s spokesman was later unable to identify what form of help the government would give businesses other than moral support.