Deposit return: it seemed like a simple idea.

Billions of people in the world are already doing it. What could be so hard, or wrong, or complex about it? It would be just like the old days when people use to get a few pennies back every time they returned an empty Barr's bottle, a scheme which only ended in 2015 because of lack of consumer uptake.

Yet to get something to function that does that simple act, seems to be proving inordinately difficult.

The Deposit Return Scotland scheme planned to roll-out in six months time has been declared a “catastrophe” by Fergus Ewing, who likened it to Titanic about to “hit the iceberg.”

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In the last week, as we have approached the deadline for producers to register, we have a lawyer, Aiden O’Neill, warning that the DRS “could create an unlawful barrier with the UK” and Scottish secretary Alister Jack urging the Scottish government to pause the roll-out and saying it is “not too late to think again”. We have heard various England-based producers declare that they will stop supplying Scotland – and how that will restrict consumer choice.

Who is to blame for this unfolding disaster, and is it really all that catastrophic? Green minister Lorna Slater has become the chief fall guy for a scheme first provided for in the climate change Scotland Act and announced by the first minister in 2017, and already delayed several times.

But some critics point to Circularity Scotland Ltd, saying that this arm’s length organisation is chiefly made up of figures connected to large industry, led by a former Chair of KPMG. To be a member of this “membership-led” entity you have to be placing more than 10 million containers onto the market in Scotland annually.

This, say some, is devised by big industry for big industry. As such it conforms to a pattern where environmental schemes in Scotland too often seem to benefit big business and fail to work hard enough for the small or local.

As someone seriously concerned about the growing timebomb of plastic waste, who would very much like to see a scheme in place as soon as possible, I’d like to think that a lot of the accusations are just pro-union, anti-Green political point-scoring. But, of course, that's not the whole story. The scheme seems to be beset by certain problems that are intractable and has also failed to resolve long-known flaws.

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Part of what angers and frustrates retailers and producers is the last-minute tweaking and lack of clarity so close to the scheme’s start date of August 2023.

But also, there are many issues around the scheme that have long been known. A review by a cross-party group on beer and pubs (notably including Fergus Ewing), drew attention to these in June 2022. It called for alignment and for the Scottish and UK governments to work together so that the UK remains “a single market for our brewer’s and retailers’ businesses”. It called for phased introduction and recommended the tackling of plastics initially, followed possibly by glass.

Was it the Scottish Government's desire to nail the most “ambitious” DRS in Europe that has driven it not to tackle these points? Or a belief that these problems would ultimately represent no more than teething problems? Are they hoping to ride this out, thinking that deposit return may be the smoking ban of our times, a policy criticised for its possible impact on pubs and bars, but that a few years down the line was widely seen as a good thing?

Even if that's so, there are issues besetting the scheme that appear unresolvable and out of Scottish government control. That “unlawful barrier” is not Scotland’s choosing, but could force a delay. We have to, as many have said repeatedly, align, to create a "single market". That alignment would mean waiting two more years, for the UK government is dragging its heels and its DRS is not due to start till 2025.

The 2022 cross-party group report, acknowledging the economic and energy price crisis we are in, called for more review. That may seem fair enough, though something in its conclusion stood out to me. “The end goal of net zero remains the same," it said, "but we need to pause to reconsider whether the DRS in its existing shape and form can be a viable part of getting us there and, if so, how we should implement it.”

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Yes, we need to get things right, but we need to not spend too long in our pauses. This is also not just about net zero. It's about the gathering impact of plastic and microplastic waste themselves.

This scheme has already been delayed and delayed. If we pause again, we have to remember that plastic pollution does not pause just because we are in difficult economic times. Billions of bottles are discarded as waste, some of them ending in landfill, some finding their way to our seas, some breaking down into microplastics that will, as research has shown, to ultimately make their way into our air and our food, our bodies and those of most other living things.

That is why we need the Scottish Government to get a scheme over the line that isn’t a shambles – and the UK Government to hurry up and achieve that too.