Today Gordon Brown has attempted to navigate the binary choice of Whitehall rule or nationalist separation by calling for a third way for Scotland’s future. In advocating home rule, Brown has reignited arguments over whether the way to save the Union is through fully blown federalism.

Despite some progress in recent decades, we still have an incredibly centralised state. Earlier this week George Aylett put forward his case for a federal UK on this website. I grew up in South Wales, and I am now a councillor in Manchester; I have seen the benefits of devolution through the Welsh Assembly and have been a passionate advocate of DevoManc; I support the principle of making decisions as close as possible to the people it affects. However, federalism is an altogether different beast and such a fundamental change to our constitution requires further thinking before we offer our support.

In my view, proponents of federalism face five main challenges:

How will a federal UK benefit our economy?

The Clinton mantra of ‘It’s The Economy, Stupid’ may have its critics these days, but huge swathes of the population base their political choices on how it affects what’s in their pockets. Independence for Scotland last time around was largely fought off over concerns about the economy. Federalists will need a strong economic case for a federal UK.

Can you bring the four nations with you?

There is no such thing as ‘forever’ in politics, but a fundamental change to the UK constitution required by a shift towards federalism would surely require trust that it would be given a significant period in which to evaluate its success – Scottish nationalists would need, at least in the short term, to take independence off the agenda. Is this achievable?

Clearly there is significant discontent with the Union in Scotland. Latest polls range from 43% to 47% support for independence, and large numbers of those against independence are unconformable with such a centralised state but there is very little clamour in Wales for independence or for the balance to be tipped back towards more Tory rule from Westminster. As a result, breaking up the union is not popular and support for a federal settlement could be achievable. However, is there any real clamour for change in England? How does this affect the very delicate situation in Northern Ireland?

Is this the right time for Labour to be discussing federalism?

In calling for a second referendum, Nicola Sturgeon is playing a high stakes game, pitching Theresa May against – what she believes to be – the will of the Scottish people. If a second referendum takes place before the next General Election, one way or another, the issue of federalism could be dead in the water. As an opposition party in both Westminster and Holyrood, what can Labour do to get a third option of federalism on the ballot for any future referendum?

What powers should be retained by Westminster?

We now turn to more practical concerns about the implementation of federalism. Federal systems reserve certain powers in their national parliaments usually, but not limited to, defence and foreign policy but given major grievances between Holyrood and Westminster on issues such as Trident and Brexit, would retaining these powers in Westminster resolve the tensions between Scotland and London? Should other powers be retained by Westminster? Would we need to establish an English Parliament or are we going to look at regional government once again?

How can we guarantee redistribution to our poorest regions? 

As socialists and social democrats, Labour Party members would – quite rightly – only support a system that distributes from richer areas to poorer areas. Like Robin Hood in reverse, the Tories have spent the last seven years redistributing in the opposite direction. Local councils in the north and in big cities have had their funding slashed and the new school funding formula will hit poorer parts of England even further. Under federalism, how can we guarantee fair funding of public services?

If supporters of federalism can answer these questions, they’ll have gone a long way towards providing a viable alternative to breaking up the union.