Stephen Flynn has told Andy Burnham to "bring it on" and allow a second independence referendum, as the SNP opened its annual conference in Aberdeen with a direct challenge to the prime minister.

The Economy, Tourism and Transport Secretary, who moved from Westminster to Holyrood after May's Scottish Parliament election, used the opening speech to demand that voters be given a "constitutional choice".

"Our message to Andy Burnham is simple," he told delegates. "If he believes the United Kingdom status quo is worth saving – then bring it on, and let the people of Scotland decide."

The challenge comes a day before Mr Burnham is expected to visit Scotland.

A battle of visions

Mr Flynn framed the coming debate as a choice between "the ambition of the Scottish National Party versus a narrow Westminster vision".

The SNP supports an independent Scotland inside the European Union, while he claimed the Westminster parties favoured an "old idea of what the United Kingdom once was".

"We are the party of independence," he said. "We have a vision for Scotland. Not rooted in memories of a country that was, but of what a country can be."

First Minister John Swinney wants another referendum held before 2031, and has already said he believes Mr Burnham will be the last prime minister of the United Kingdom. The party is planning what it describes as its biggest pro-independence campaign since 2014.

'Eighth prime minister to tumble'

Mr Flynn linked the prime minister's political survival directly to the future of the Union.

He pointed to May's elections, in which the SNP won a fifth consecutive Holyrood victory and Plaid Cymru became the largest party in the Senedd, ousting Labour from power in Wales. Sir Keir Starmer stood down as prime minister after Labour's poor results.

"There is no doubt that the electoral success of our friends in Plaid in Wales, and of ourselves here in Scotland, ended the reign of yet another Westminster prime minister," he said, describing Sir Keir as the "eighth prime minister to tumble" during the SNP's time in government.

That, he argued, "explains why Andy Burnham is so obsessed with John Swinney and the Scottish National Party".

Labour's response

Mr Burnham used his own conference speech last month to declare that he was "utterly determined" not to be the prime minister who presided over the break-up of the UK.

Earlier this year he was forced to clarify remarks that appeared to suggest another referendum could take place in certain circumstances, and he has since made clear he does not support one.

Scottish Labour deputy leader Dame Jackie Baillie dismissed Mr Flynn's challenge. "This is nothing more than a distraction from the SNP, who do not want anyone to focus on their poor record in government," she said.

She said the party could instead have used its conference to set out plans for fixing the NHS, restoring Scotland's education system and improving public services.

The constitutional deadlock

Under the 2022 Supreme Court ruling, Holyrood cannot legislate for an independence referendum without Westminster's agreement. That leaves the SNP reliant on persuading – or pressuring – a UK government to grant the powers needed for a legal vote.

In 2014, Scotland voted to remain in the UK by 55% to 45%. Opinion polls since have frequently shown the country closely divided.

For the SNP, the Aberdeen conference is an opportunity to rally activists after its election win and to turn constitutional momentum into a sustained campaign. For its opponents, the focus remains on hospital waiting times, schools and the cost of living.

The conference continues until the weekend, when Mr Swinney is expected to deliver the leader's keynote speech.