The favourite to succeed Jeremy Corbyn as leader of the Labour Party will propose that Britain’s archaic and confusing conventions are replaced with a written constitution that would set in stone a new devolution settlement.
That settlement would deliver a “radical redistribution of power, wealth and opportunity” to every corner of the UK, according to Sir Keir, arguing that the Tony Blair and Gordon Brown governments left the job half done.
“The status quo is not working,” he will say in a speech in London, ahead of visits to Scotland, the northwest and Wales over the coming days.
“People are crying out for more control, power and say over their own lives and local communities. This can’t be delivered by tinkering around the edges or with short-term fixes.”
The proposal of a federal structure is one previously put forward by Mr Brown, although the idea dates back to Winston Churchill more than a century ago.
Sir Keir, who abandoned campaigning for four days after his mother-in-law suffered a serious accident, will not set out the details of the new structure, or of the powers to be devolved.
Instead, he will call for the UK to follow other developed nations by drawing up a new written constitution, which would be devised by the “great and good” in a constitutional convention.
The idea is partly aimed at heading off the increasing possibility of Scottish independence after Brexit, but also at recognising the desire of people across the UK for greater control of their lives, previously displayed in the vote to leave the EU.
“We need to end the monopoly of power in Westminster and spread it across every town, city, region and nation of the United Kingdom,” the shadow Brexit secretary will say.
“This will involve building a new long-term political and constitutional consensus. I believe that could best be built on the principle of federalism.”
All three candidates spoke up for an open immigration system, with Ms Nandy backing free movement and Ms Long-Bailey dismissing claims that migrants depress wages.
Ms Long-Bailey said it was right to “look at proportional systems of voting”, while Ms Nandy called for trials of proportional representation “in areas where it doesn’t automatically benefit” Labour.
Ms Thornberry was typically outspoken, saying: “I hate the SNP. They’re Tories wrapped up in nationalist clothing.”
And she argued that she was the candidate who never struggled to get on the airwaves, explaining: “I am clear, concise, strong ... I don’t faff around.”
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