Rolling coverage of the day’s political developments as they happen

• UK would not back US bombing of Iran cultural sites – No 10
• No 10 lobby briefing - Summary
• ‘We must win or die’: Angela Rayner stands for deputy Labour leader
• Rayner’s speech - Summary

2.33pm GMT

Ian Murray, Labour’s only surviving MP in Scotland, is preparing to enter the contest to become Labour’s deputy leader on a platform of constitutional reform and countering nationalism.

Murray, an arch critic of Jeremy Corbyn’s and an opponent of Brexit, is expected to signal his intention to run tomorrow after being asked to stand by other Labour MPs. His plans to run are thought to depend on getting sufficient early nominations, but it would fuel the brewing conflict between the party’s pro-Corbyn wing and its centrists.

There are no doubts that constitutional and nationalist issues are engulfing our politics. I have the experience and knowledge of dealing with both, and the Labour party has ducked this issue for too long. English nationalism from the Tories and Scottish nationalism from the SNP are squeezing the Labour Party and we must stop it.

[The] danger for our party across the UK is what I have been warning of since 2015. If we don’t tackle the big constitutional issues with reference to our own values and the national interest, then we lose our core purpose.

2.23pm GMT

After listening to Angela Rayner’s speech this morning, my colleague Kate Proctor concluded it was hard to see why she was running for the deputy Labour leadership when she might be a strong candidate for leader. (See 12.23pm.) It is not hard to see why. It’s a good speech, with some compelling lines and a superb opening.

Here is the opening.

I wanted to make this speech here, on the estate where I grew up and lived for most of my life.

I talk about my background because for too long I felt I wasn’t good enough; I felt ashamed of who I was. It took me time for that shame to turn into pride.

We fell into the trap of describing a platform of revolutionary change. By the standards of recent politics, it was, and rightly so.

But actually, we could have told a simpler story.

Many of the friends I grew up with, my own family even, voted to leave the EU.

They felt like we treated them as embarrassing aunts or uncles.

There are also lines beyond which there is no dialogue and no compromise possible.

And the first line in the sand is antisemitism.

Nor should we take for granted the new voters we have won over, any more than we should have done those we have lost.

For all that’s said about London, we made no net advance in seats there either. We faced a fight to hold others like Dagenham and Rainham - a place that, like my own constituency, has so much to gain from a Labour government, but where too many people felt our party had lost touch with them.

Across Europe social democratic parties are collapsing.

The once mighty German SPD, the biggest and oldest social democratic party in the world is on 11 percent

I don’t pretend that I have all the answers. That is the point of being a collectivist. That by the strength of our common endeavour, we achieve more than we do alone.

That final sentence is a quote from the new Clause IV introduced by Tony Blair.

I owe much of my life to Labour.

The Labour governments that provided the welfare state, Sure Start, and the minimum wage, which gave me the help I needed to not just survive but succeed.