Nicola Sturgeon renewed her vow to tear up the UK today as she unveiled plans to hike taxes to bankroll a £118billion spending splurge.

Launching the SNP manifesto, the Scottish First Minister insisted there must be a fresh referendum on independence.

Miss Sturgeon told the event in Perth that Theresa May's refusal to hold a vote on the issue before the process of leaving the EU is complete was 'completely unsustainable'. She said if the SNP wins a 'majority' of seat north of the border on June 8 it will 'reinforce her mandate' to force a ballot as early as Autumn next year.

However, she did appear to hint that she could give some ground on the timing if Brexit takes longer than expected.

The intervention comes amid rising concerns that a hung parliament opening the door to splitting the UK. Jeremy Corbyn said this week that he would 'open discussions' with the SNP about another referendum if he becomes PM after June 8.

Meanwhile, Miss Sturgeon has repeatedly refused to deny that she would demand the concession in return for propping up the veteran left-winger in power.

Nicola Sturgeon told the event in Perth today that Theresa May's refusal to hold a vote on the issue before the process of leaving the EU is complete was 'completely unsustainable'

The SNP leader insisted that a new referendum on independence should be held as early as Autumn next year

The manifesto also pledges to reintroduce the 50p top rate of income tax nationally

Miss Sturgeon was cheered as she told SNP activists at the launch this morning that 'extreme Brexit' was a unacceptable risk for Scotland

Miss Sturgeon was cheered as she told SNP activists at the launch this morning that 'extreme Brexit' was a unacceptable risk for Scotland.

'That is why I believe so strongly that at the end of the Brexit process - not now, but when the terms of the deal are known - Scotland must have a choice about our future; a choice between following the UK down the Brexit path or becoming an independent country,' she said.

'There is just too much at stake for Brexit simply to be imposed on Scotland, no matter how damaging it turns out to be.

'Our future must be decided by us, not for us. Last year's Holyrood election delivered the democratic mandate for Scotland having such a choice, and the recent vote of the Scottish Parliament underlined it.

'If the SNP wins a majority of Scottish seats in this election, that will further reinforce our mandate.

MAIN POINTS FROM SNP MANIFESTO Hold a new referendum on Scottish independence as early as Autumn next year

Give Scotland control over its own immigration policy

Raise taxes to fund £118billion in new spending over the next five years

Oppose cuts to welfare and end the freeze on benefits increases

Support triple lock on pensions, which sees them rise by the highest out of inflation, average earnings, or 2.5 per cent Advertisement

'And in these circumstances, any continued Tory attempts to block Scotland having a choice - when the time is right and the options are clear - would be democratically unsustainable.'

Asked whether she stood by her previous timetable for rerunning the 2014 independence referendum, Miss Sturgeon said: 'I've said at the end of the process.

'I've said that for a reason – because it's important people have clarity about Brexit and what it means, and they have clarity about the options.

'I said autumn 2018 to spring 2019 for a reason, because that's when Theresa May is saying the Brexit process will end; so I've taken her at her word. If that changes then of course we will have to consider our timing in light of that.'

The comment raises the prospect that Miss Sturgeon could ease her demands if a new Brexit deal is phased in.

The manifesto also pledges to reintroduce the 50p top rate of income tax nationally - despite the SNP opting to freeze it at 45p north of the border.

In total, the party wants to raise an extra £10billion - while loosening borrowing rules will free up tens of billions more.

The SNP said its spending plans amounted to £80billion, including ending the cap on public sector pay rises and scrapping the freeze on benefits.

Pending independence, the blueprint says SNP MPs at Westminster will push for Scotland to have control of its own immigration policy.

Speaking on the BBC Radio 4 Today Programme earlier, Miss Sturgeon's Westminster deputy Angus Robertson said the SNP will launch a tax raid to raise cash for public services.

He said: 'There are additional tax revenues which we will be outlining in the manifesto, including an additional rate of income tax to be seat at 50 pence right across the UK.'

Launching the SNP manifesto today, the Scottish First Minister insisted there must be a fresh referendum on independence

However, Miss Sturgeon did appear to hint today that she could give some ground on the timing of a referendum if Brexit takes longer than expected

SNP supporters queued outside the venue in Perth today before going in to cheer Miss Sturgeon as she unveiled the manifesto

But he was grilled over why the SNP, who are in government in the Scottish Parliament in Holyrood, has not used its devolved powers to increase taxes.

Mr Robertson said: 'The Scottish government has already made announcements about what it is going to be doing with its tax raising powers, but we should remember that the main economic levers are exercised in Westminster.'

But the plans will fuel criticisms that the SNP are 'not credible' because last year they dropped their election promise to raise the income tax threshold to 50 pence in Scotland.

Nicola Sturgeon and Angus Robertson, pictured yesterday campaigning in Lossiemouth, unveiled the SNP's manifesto today

Mr Robertson tried to bat away these concerns, and said that in Westminster the SNP will vote 'to end austerity, to end cuts damaging our public services and pushing people into poverty'.

The SNP's leader in the House of Commons also said his party wants Scotland to be given control over its own immigration policy.

He said immigration is 'profoundly important' to the economy north of the border and the SNP does not want to cut it.

He added: 'We want the opportunity for people to come and to go, and what we certainly don't want is a restrictive immigration policy imposed on us by Westminster which is going to damage our economy and our public services.'

But he was unable to say if he wants immigration to go up, and if so by how much.

Mr Robertson is facing a tough battle from the Tories to keep his seat of Moray in the General Election.

He said the election is a 'two horse race' between the SNP and the Tories in Scotland as he tried to win over voters by promising to protect benefits and pump more money into services.

Nicola Sturgeon unveiled plans to hike income tax to bankroll a public spending splurge in her party's manifesto today