The deal agreed between Boris Johnson’s government and the EU would mean a “much harder Brexit” than previous proposals, Nicola Sturgeon has said.
An agreement between the UK and EU was announced on Thursday morning, but is still to face a vote in the Commons.
The first minister said it was “clear that Scotland is being treated unfairly”, and confirmed that SNP MPs “will not vote for Brexit in any form”.
And Ms Sturgeon said a “much harder Brexit beckons if this deal passes”.
Mr Johnson said the “great new deal” would see the UK “take back control of our laws, borders, money and trade without disruption”.
However, it is unclear if the proposals will pass a vote of MPs on Saturday, with the DUP saying they still cannot support it.
The deal was announced by Mr Johnson and European leaders via Twitter on Thursday morning, ahead of a summit in Brussels.
It removes the much-disputed “backstop” proposals for the Irish border post-Brexit, and would instead see Northern Ireland remain in the UK’s customs territory – while adhering to a limited set of EU rules on goods. Representatives in Northern Ireland would be able to decide whether to continue this arrangement every four years.
European Commission President Jean-Claude Juncker said it was a “fair and balanced agreement”, calling for the Brexit process to “move on”.
Mr Johnson said the “great” new deal “allows us to get Brexit done and leave the EU in two weeks’ time, so we can then focus on the people’s priorities and bring the country back together again”.
However, opposition parties in the UK have been critical, with Labour leader Jeremy Corbyn saying the deal sounded “even worse” than what was negotiated by the previous prime minister, Theresa May”.
And Ms Sturgeon said Mr Johnson’s plan would lead to a “much harder Brexit”, highlighting that people in Scotland voted for Remain by 62% in the 2016 poll.
The SNP leader had always been clear that her 35 MPs would reject any deal brought back by Mr Johnson which takes the UK out of the EU’s single market and customs union.
Reiterating this on Thursday, she said: “We support efforts to ensure peace and stability on the island of Ireland, in line with the Good Friday Agreement, which must be respected.
“At the same time, it cannot be right that Scotland alone is facing an outcome it did not vote for – that is democratically unacceptable and makes a mockery of claims that the UK is in any way a partnership of equals.
“The Brexit envisaged by Boris Johnson is one which sees a much looser relationship with the EU when it comes to issues like food standards, environmental protections and workers’ rights. That is not the future that I or my government envisage for Scotland.”
Ms Sturgeon also repeated her call for a second independence referendum to take place in 2020, saying it was “clearer than ever that the best future for Scotland is one as an equal, independent European nation”.
She told her party conference on Tuesday that she would submit an official request to the UK government for an agreement to hold such a referendum by the end of this year.
However, the UK government has repeatedly said it will not do such a deal, saying the 2014 ballot was a “once in a generation decision”.