I'm still backing a Scottish deposit return scheme. Not because I want Scotland to be ahead of England, or even different – but because I don’t want us to have to wait till 2025 before we see fewer plastic bottles on our beaches or smashed glass scattered in our parks.

The latest blockage to the scheme revolves around glass. The UK Government, it turns out, has told Scotland that the DRS can go ahead, but cannot include it - and that's essentially because the UK deposit return scheme scheduled for 2025 will not include glass.

The response from Scottish Government was hardly surprising. Humza Yousaf called it “an attempt to undermine devolution”. Lorna Slater said it “would ride roughshod over the devolution settlement.”

I would agree – but I would also agree with those that say that the SNP and Greens have done their own bit of spin and play on the issue. 

And this is the problem. This latest trouble with glass is a reminder that when it comes to politics, we only see through a glass darkly. Many of the arguments around the DRS seem mired in politicking. Whenever anyone makes a pronouncement, you have to ask yourself to what degree they may be lobbying for industry, or taking a position on the basis of a unionist or pro-independence view.

Cards on the table, what I’m chiefly interested in is that there is less plastic, metal and glass waste - not just across Scotland, but the whole of the UK, and ideally. Most important to me is that we get plastic deposit return scheme that helps stem the flood of macro plastics, which then disintegrate to microplastics and contaminate our environment, food and even blood.

READ MORE: Tory MSP says deposit return scheme could go ahead with glass included

READ MORE: UK Government will permit Scottish deposit return scheme – but without glass

But I also do understand why glass is important. Its frequently said that the benefits of glass deposit return are complicated by the fact that there is already a relatively successful system of kerbside recycling. There are some out there on Twitter who are even saying we have one of the best recycling systems in the world. But this is far from true.

One area in which we are failing is in what’s called ‘closed loop’ recycling, the kind of system where the glass is actually used to make new glass, rather than other lower-value substances like fibreglass and sand. Britain's closed loop recycling rates for glass are just 43 percent, compared to 61 percent in France and 77 percent in Germany.

Closing the loop is what deposit return is all about. It's about what most of us think of as true recycling: glass from bottles being reused as glass in bottles.

We are often told that the scheme is complex, but it seems the bigger problem is that everything around the scheme is complex, especially the politics – and with so many people mouthing off it’s often hard to know what’s what.

But there are a few things that one can probably be fairly confident are true. The first is that there are businesses that will struggle because of this scheme, and they should have been put through less confusion and uncertainty – but at least now many of the smaller producers have been excluded.

The second is that we need to make a shift away from a disposable way of living, towards a circular economy, with more closed loops, and deposit return is a significant step in this.

And the third is that this potential scuppering of DRS does represent an undermining of devolution - one that was almost inevitable once the UK Internal Market Act was in place. When it first passed, there was talk about how it might cause a ‘race to the bottom’, in which those parts of the UK market with the lowest standards would dictate for all - and this has now come to pass.

Why is it, you have to ask yourself, that the European Internal Market has managed to allow for a multiplicity of deposit return schemes, but it looks like the UK Internal Market can’t handle much in the way of difference? 

Meanwhile, Scotland is being portrayed as the difficult party, wantonly forging ahead with a scheme that actually roughly corresponds to what everyone else originally planned in the first place. Wales still has glass in its plan (though good luck to them with keeping it there), and England and Northern Ireland only just recently eliminated it.

On one level it feels as if our friends have reneged on a pact - though, of course, the other version of this story is that ditching glass was just the most pragmatic decision.

But what's most troubling is the language being used around this - talk, for instance, of Westminster having Scotland on a leash that can be tugged. Many of us would like to be able to talk instead about improving circularity, carbon intensity and recycled content. But, of course, that stuff is just the backdrop. Really this is about power and who gets to decide - and when that's at stake, it's always going to be a case of smoke and mirrors.