ONLY the SNP can stop the Tories diminishing the powers of the Scottish Parliament and reversing “the gains of devolution,” Nicola Sturgeon has claimed.

Speaking ahead of the SNP’s manifesto launch in Perth this morning, the First Minister conceded the polls still show Theresa May will continue as Prime Minister.

Sturgeon warned Scots that realistically, next week they will be casting a vote for who will make the better opposition, not for who will form the government.

The party were due to launch their manifesto last week, but rescheduled after the Manchester terrorist attack.

A number of key pledges have already been revealed, including proposals to keep Scotland in the single market as part of the Brexit negotiations, and protecting the triple lock on pensions and winter fuel payments. The National can also reveal that the manifesto will commit the party to opposing any attempt to drag the UK out of the European Convention of Human Rights (ECHR).

Speaking ahead of the launch at Perth’s Concert Hall, Sturgeon said Scotland needed “strong SNP voices at Westminster”.

She said: “While the polls have narrowed, the Tories are still on course to win the election.

“Labour proved beyond any doubt that they were unable to provide the opposition needed to keep the Tories in check in the last parliament.

“Only the SNP can provide the strong opposition that Scotland needs to protect our schools, hospitals and vital public services from deeper Tory cuts and further damaging austerity.”

She added that an SNP victory in Scotland would “strengthen the country’s hand” in Brexit negotiations.

The First Minister added: “Central to our manifesto are three core pledges which underpin why it is so important for people across Scotland to get out and vote for the SNP next Thursday. SNP MPs will always be a strong voice for Scotland, standing against Tory cuts. We will set out a clear plan to end mindless Tory austerity across the UK and to invest in public services.

“While the Tories are set to plunge Britain into Brexit without a clear plan, a vote for the SNP will give us a strong hand in the Brexit negotiations to ensure Scotland’s interests – on jobs and our economy — will be heard at the top table. Regardless of whether you voted leave or remain, a vote for the SNP at this election is a vote to ensure Scotland’s interests are protected throughout that process.

“And the SNP will always make the case that Scotland should have the right to make our own decisions on Scotland’s future — and stand against any Tory attempts to diminish the powers of our Scottish Parliament or reverse the gains of devolution. Today’s manifesto launch will set out the real alternative to Tory cuts and Brexit chaos. That is the positive case we will take to voters next week.”

Scottish Labour leader Kezia Dugdale said the SNP had spent the last 10 years “obsessively campaigning for independence”.

She said: “At the General Election people can send Nicola Sturgeon a message that she should focus on the day job, rather than forcing another independence referendum that people in Scotland don’t want.”

The ECHR is enshrined in the Scotland Act 1998, ensuring human rights are protected by the Scottish Government and all Scottish legislation. There is a growing fight ahead about repealing the Human Rights Act, and what role the Scottish Parliament will play in that.

If it is repealed and replaced with a British Bill of Human Rights then it could need a Legislative Consent Memorandum under the Sewel Convention, which is supposed to stop Westminster legislating on devolved matters in Scotland without the consent of the Scottish Parliament.

Though that itself is in question after the recent Supreme Court on the EU and MPs being given a vote on triggering Article 50.

The SNP’s depute Leader Angus Robertson told The National that any attempt to “abolish the Human Rights Act and remove us from the ECHR risks undermining the entire devolution process”.