JOHN McDonnell has outlined plans for "transformative socialist change" under a Labour Government, as he poured cold water on SNP proposals for a second independence referendum. 

The shadow chancellor signaled a mass expansion of the state if Jeremy Corbyn secures the keys to Number 10, with an additional £3 billion-plus in spending for Scotland.

He previously said a Labour Government would not stand in the way of a second independence referendum if there was a mandate to hold one.

But at a rally in Glasgow, he reiterated that this would not be a priority, insisting Labour would have "enough on its plate" to deal with.

Nicola Sturgeon has said she wants to hold another vote in the latter half of 2020, with legislation currently making its way through Holyrood.

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But Mr McDonnell insisted a second poll would be a distraction from poverty, the Brexit fallout and the threat climate change poses to the future of humanity.  

There has been widespread speculation a minority Labour administration would grant the Scottish Government the power to hold a referendum in exchange for SNP support in the Commons.

It came as Mr McDonnell said the expansion of "universal basic services" will be at the heart of Labour's election manifesto. 

He even raised the prospect of following in the footsteps of Scottish leader Richard Leonard, who outlined a long-term target of free bus travel for all earlier this year.

The shadow chancellor promised a "strong social security safety net", as well as wider structural changes which would "rewire the whole economy". This would be funded by a "honest and fair taxation system", with income tax hikes for the top five per cent of earners.

In the 2017 general election he said Labour's spending plans would have meant an additional £3 billion of cash going to ministers in Edinburgh under the Barnett formula.

Speaking to supporters in Glasgow, Mr McDonnell pledged: "For the next election, hopefully in a few weeks time, we will go further. Because there are things that are too important to leave."

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Elsewhere, Mr Leonard outlined plans for major land reform measures in Scotland, including capping the amount of land someone can own and introducing residency requirements. 

He said this would "discourage absentee landlordism - even if you happen to be the President of the United States of America".

He also pledged an overhaul at Holyrood, saying there would be changes made to the way the block grant Scotland receives from Westminster is calculated.  

Meanwhile, Mr McDonnell hit out at Boris Johnson and his government of "far right extremists", and accused the SNP of passing on Tory austerity and "extraordinarily distressing" cuts to local councils.

He said a second independence referendum would not be a Labour Government's priority if the party wins any snap general election.  

He said: "In the first period of a Labour government we have got enough on our hands. Do you really want to distract us from those big issues - when you've got children living in poverty, when you've got climate change threatening the very existence of our future generations, when we're inheriting such a mess from the Tories? That's going to be our priorities. And I actually think they're the priorities of the Scottish people."

However he repeated his insistence that Labour would not stand in the way of another referendum if there is a mandate for it.

He said: "If there's a mandate from the Scottish people - and the Scottish people will determine that mandate - we've said we won't stand in the way of it."  

He said Labour "would want the Scottish people themselves to have that debate about what that mandate should be, before any request is put in".

It is not clear what this would mean in practice.