Never plan ahead unless you are prepared to throw away. That’s a lesson I have had to learn over and over again.

As I’ve said elsewhere, I had a plan to talk about the trend of government “doing deals” instead of offering the same policy options to everywhere, both through devolution and for new council housing.

Never mind that the letters were falling off from behind Theresa May, her housing policy proposals didn’t once mention the deals government have been working on with some councils for many months now.

I don’t think that means that the deals are not going to happen, just that government thinking has bypassed them for now. Rather than hark on about something that is on the back burner, I will try and talk about devolution more widely, in particular a wide view of what it could mean for the country (and by that I mean England) as a whole.

Now that the dust is settling on the first tranche of devolution deals, with elected metro mayors in a number of larger city regions, I think we need to calmly and reasonably look at where devolution could be leading us as a country and comprehend what this new multi-speed system is going to look like.

We should first take a couple of steps back. Right back to 1974 in fact and forward through many acts to the creation of many of the local government systems we see today. What we need to understand is that England is already a diverse system, with London having its own rules and the rest of the country being split into unitary systems, two tier systems, metropolitan boroughs, non-metropolitan boroughs. Some authorities have a committee system, some a cabinet system and some elected mayors.

The impact of these different systems and the negotiations that brought them about means that councils can be big or small, self contained or not. In just one example, Leeds City Council covers a huge, diverse area. You can walk around the edges of the Leeds district, only very occasionally interacting with something that isn’t countryside or a village. Even the urban join with Bradford isn’t that wide, when you look at it or walk it. Manchester City Council covers a much smaller area, is bordered by Salford and Trafford, both themselves large urban areas part of what the layman would call “Manchester”, although be careful doing that in some parts of Salford!

The reasons behind this are tied up with history and practically ancient politics. Yes, it happened that Manchester and Salford centres grew up next to each other, and Newcastle and Gateshead for that matter. There are historical and political reasons Herefordshire is a unitary authority and Worcestershire isn’t and why it is Herefordshire and Worcestershire, not “Hereford and Worcester”.

The point is, the structure of local government has evolved to both reflect and create very different areas and has done so because government has usually been remarkably pragmatic and open to what they perceive to be the requirements of the local area. But most powers given to councils have been across the board, with only tinkering or one off payments between them. Authorities have often been able to come to their own conclusion on how they wish to run services, but not which services they choose to run.

This was even the case in local authorities that opted to have elected mayors; it was simply another way of administering the same services. In the early 2010s two things changed. One is very techie but could be important in all number of ways- in 2011 councils became able to do anything an individual could do. So they could set up companies more freely, take on other non-statutory responsibilities and were generally more free to act. It is worth pointing this out because really there is nothing apart from finances stopping many authorities from doing what they want- as long as it isn’t creating taxes or go to war. But finance is the key one and we will come back to it!

The other was wider devolution- multiple authorities working together to create a combined authority. This is especially true as this often meant taking responsibility for central government functions and delivering them locally. The list of potential responsibilities is long, but let’s for the sake of brevity state that anything apart from taxing and warring was on the table. Everything was up for grabs, but that’s where the deal comes in. Each different set of authorities taking part had to come to an agreement first with each other and then secondly with central government about what they would like to control and how they were going to be measured on whether they have succeeded.

This means, especially as more areas catch up with the outriders on devolution, that different places have different deals. One place may have a deal to look after health and social care funding, whilst another may not. One may put the oversight of Police into the metro mayor’s hands, another may stick with a police and crime commissioner (for as long as they last). One may have an intricate deal on new housing delivery, another may have just received a cash amount to unlock housing sites. A third may not have considered housing at all in their deal. Many may soon try to franchise bus services, but others may choose to leave that alone.

All this means policy making at the national level will have to become a lot more cautious about what and where central government can make changes- law and guidance will have to be clear about where it applies- which probably means exemptions coming out of your ears. It also means people moving from one devolved area to another will not necessarily have the same entitlements, support or interactions with their local representatives.

Areas that do not have a deal will still be covered by policy decisions made at Westminster, but with fewer and fewer areas covered (particularly populated areas) this is going to mean a very different type of policy making. It could, over time, mean that some Westminster policies and debates become quite tailored to the needs of some of those areas. Assuming it will mostly be rural and semi-rural areas left un-devolved it may mean that some debates in Westminster become focused on those areas.

Indeed, this could even mean that smaller urban areas not in devolution deals will be ignored because the “non devolved areas” are seemingly represented by the views of rural and semi-rural areas. It may also lead to some strange variant of the West Lothian Question- why should Greater Manchester MPs vote on a topic that doesn’t affect their area?

Those on the outside of devolved areas may well look at the extra funding being received with envious eyes. Indeed, this is arguably one of the reasons the Leeds City Region has ended up in the quagmire it has. Those who want to say “me too!” or “me as well!” need to have their cases looked at, but there needs to be some clear and consistent direction from government about who can be involved in devolution and who cannot.

In whatever scheme there will be places outside of devolution. Jonn Elledge’s piece on Herefordshire neatly illustrates that they can and probably will feel left out and something may need to be created for them- I’m suggesting calling it devo-min.

To put that another way, if devolution isn’t for everybody (and that is the mood music out of the government) then the government does have to be clear how the world will work for those left outside the devolved areas as well as accept that their decision making power has been reduced for large parts of the country. Politically, it would be better if this looked like an offer rather than telling them “things will stay the same”, but that’s for the politicians to decide.

I want to come back to finances, because it is clear that the next step for devolution is going to be fiscal. Metro mayors are not going to be happy with a begging bowl approach for long- they are going to want to set taxes. Given the rather terrible state of council tax this isn’t exactly unreasonable; practically anything save a poll tax would be better than further tinkering with council tax.

So we may see different tax rates and indeed different tax styles in different areas. Maybe a land value tax somewhere and an additional income tax somewhere else. This doesn’t necessarily mean the overall tax burden will increase, but there will be pressure to allow metro mayors to levy their own funds to pay for the services they feel people want.

I can imagine the Treasury in particular will try hard not to accept this, but past a certain point it is going to be hard to resist. It will be fiscally hard to control (isn’t that the point?) but could lead to significant buy-in if people recognise the links between their payments and the services they receive. I suspect as a final statement, the Treasury will argue that any authority with fiscal powers should be allowed to fail.

So a system where devolution has reached its apex will be characterised by diversity, but we have to remember that we had a diverse system to begin with. We’ve coped with it well enough so far. Policies in one place may simply not apply in another- I think we can probably cope with that, although newspapers will no doubt be up in arms about postcode lotteries. It certainly won’t look federal, because there will be swathes of the country where devolution doesn’t apply. Those areas may feel hard done by unless they have some individual offer-whether it is a form of control or a guarantee of only their MPs setting the rules for those areas.

If the government doesn’t like the look of that they could try and put the genie back in the bottle by limiting the ambitions of devolved areas. If that’s the case, we could see something much more like the old metropolitan county councils, which would be a crying shame. This would be a two-tier system, with perhaps limited additional powers (the current agreements plus a few more, if they’re lucky), but mostly just conglomerated powers from the existing councils underneath them.

Diversity is not a bad thing, it can lead to experimentation and finding out what works. Areas that are not the same shouldn’t be treated the same (that would be an oversimplification). Some slight form of competition might be beneficial.

But we do need to have a sensible discussion about where we want to set the limits and what we need to do with the areas where devolution doesn’t apply. If nothing else, that will let the areas ripe for devolution go for it without being held back by a small number of interested parties.