What do you do with your time when you cancelled your own bid for the Labour leadership only to end up on the backbenches, unable or unwilling to serve in a Corbyn-led shadow cabinet? Judging by the latest contributions from two of the Men Who Would Be King (In A While), Dan Jarvis and Chuka Umunna, you start to sketch out your own alternative strategy for the Opposition.

In the last 24 hours both men have urged their colleagues to take up the devolution agenda championed thus far by George Osborne. In a speech yesterday, Jarvis argued that:

‘I don’t want to spend the next five years rubbishing the idea of a Northern Powerhouse. I want Labour to lead the debate about how we build it and shape it according to our values.’

While in today’s Guardian, Umunna delivers a similarly uncomfortable truth:

‘We in Labour must also face up to a tough reality. Yes, Osborne’s prospectus contains a lot of spin. But, despite the strides forward we made in the last parliament in this policy area, the fact remains that the chancellor has made a big bid for a cause on which Labour should be leading: the decentralisation of this country…’

Inevitably, both arguments are draped about with plenty of criticism of the Chancellor and the Government – for Jarvis, Osborne is guilty of ‘devo-disarray’, while Umunna attacks ‘the drip-drip devolution of conditional powers’ – but in today’s toxic Labour Party that’s essential body armour against the fatal charge of closet Toryism. Underlying both interventions is an evident fear that Labour is being divided and left behind on an essential topic.

While the latest round of welfare changes have pitted Conservative against Conservative, we shouldn’t forget that ordinarily splitting the Labour Party is the Chancellor’s tour de force. His devolution agenda has managed to divide Labour’s local government leadership in heartlands like Manchester from their national leaders in Westminster – the sight of Labour council leaders lining up to agree devolution deals with the Treasury has unsettled those with an eye on their Party’s future.

The initial reaction of the Opposition – to criticise DevoManc, for example – came unstuck when they found their own town hall base defending and engaging with the idea. It’s therefore significant that Jarvis and Umunna have both decided to push for Labour to adopt the principle and seek to further extend the policy. That is their only hope of a coherent, politically viable response – indeed, it’s a similar strategy to the Conservatives’ adoption and radical extension of Labour’s academy schools policy.

That’s not to say that Corbyn, or his endlessly furious followers, will do the same. The fact that Umunna and Jarvis have chosen to go freelance on the issue suggests that they not only worry about the existing Tory dominance of the devolution agenda, but they must also lack confidence that their leader will fight back of his own accord.