But now there is a vacancy for the Labour deputy leadership, and Labour members might try to elect somebody who is even more left-wing, so the government might be pushed to the left.

Edit: I’m not saying that a more left-wing deputy leader of Labour is necessarily a bad thing. I’m just saying I don’t necessarily believe that Starmer was happy to remove Rayner. “Better the devil you know” and all that - Rayner was a known quantity to Starmer, and she didn’t criticise his leadership too much. Now there is a risk of someone critical of the government becoming the deputy leader of Labour, which could give Starmer more problems.