FILE PHOTO: Scotland's first minister Nicola Sturgeon speaks at the inauguration of the European Offshore Wind Deployment Centre (EOWDC) off Aberdeen, Scotland, Britain Sep 7, 2018. REUTERS/Russell Cheyne

EDINBURGH (Reuters) - Prime Minister Theresa May’s plans to leave the European Union are damaging and inviable, Scotland’s First Minister Nicola Sturgeon will say on Tuesday.

Britain is due to leave the European Union in March next year, but May has said that talks with the European Union are at an impasse insisting that “no deal” is better than a bad deal.

But Sturgeon said that even if May achieved her “Chequers” plan for Brexit, the policy of taking Britain out of the single market would hurt the economy.

“The prime minister’s current position – that we must leave the single market regardless of the consequences – is an act of wilful economic vandalism,” Sturgeon will tell the Europa Institute in Edinburgh.

Scots voted to stay in the European Union in 2016 by a large margin, but Britain as a whole voted to leave. The Brexit process has since put Scotland’s devolved nationalist government increasingly at loggerheads with the UK’s Conservative leadership.

Most polls show public support for Scottish independence from the UK stuck at the same 45 percent level it has been since a 2014 vote, although a recent poll showed backing for a split has ticked up in a sign of discontent over Brexit.

Sturgeon said that May was now facing a “mutiny” from her Conservative Party at its annual conference in Birmingham this week, adding that May should ask for more time to negotiate withdrawal from the bloc.

And a disastrous few weeks for the prime minister, in which her blueprint for Brexit was rejected at an EU summit, contained a glimmer of hope, the Scottish leader said.

“The very fact that the prime minister’s negotiating position has been exposed as untenable, means that membership of the single market and the customs union must now be a stronger political possibility than at any time in the last two years,” Sturgeon will tell the Edinburgh audience.