Tomorrow it is almost certain that the council will vote to build the tram line to St Andrew Square, reversing a decision taken last week to curtail the line at Haymarket.

Today, in our Tram Lines series, we present a series of opinion pieces from our readers, giving their views on the tram project to date.

Here, Alison Johnstone MSP, shares her take on the project.

So it's crunch time again tomorrow on the trams, for at least the third time this year. This administration and its predecessors could hardly have found a more effective way to frustrate and infuriate both people who love public transport and those who don't care less about it, while single-handedly keeping local journalists in work.

The pickle the city is in brings together a toxic cocktail of dire management by officials, a contract that appears more loophole than structure, and a local administration divided between a party that sincerely wants to build the trams and one that wants to undermine them.

The catalogue of woe also includes a failure to check what services would need to be moved - and now, at last, radar scans are being undertaken. Although the digging up of services has been a bugbear of the scheme, it could all have easily been avoided.

The private company which planned to deliver the trams until the Council stepped in proposed using a newer track technology called LR55, and that would have required no utility diversions at all, just work to reinforce the gas main at Haymarket and a power cable across Leith Walk.

This more modern track system was regarded as too untested by officials, even though one estimate I've heard is that a third of a mile of this sort of track could have been laid overnight, with the roads open again in the morning. Given that the main costs have been around delay and roadworks, why did the administration not consider this alternative approach?

Still, that won't help us now, although it's just about conceivable that starting again with LR55 could even be cheaper. It'd certainly make any expansion of the network quicker, cheaper and easier to maintain.

The options we now face are all severely unattractive. Cancellation would be wildly expensive, with the city facing financial devastation: then the Scottish Government would understandably withdraw their contribution, and the prospects for an expensive court case would be strong. We'd need to find at least another £161m this year alone, the same order of magnitude as the money the city currently spends on health and social care combined.

The Haymarket option would see the city lose millions a year, a classic false economy, and Labour and the Tories should be ashamed of themselves for backing it. Finishing the line to St Andrews Square is the only plausible option, and the evidence is it would turn a profit too, but even there it's not clear whether the administration have done the required due diligence on the construction costs.

It's an impossible situation, and I quite understand why many capital residents want to scrap the scheme and probably vote every last councillor out of office. But we cannot see the city both lose out financially and not get even the start of a tram system. This is presumably the cold hard reality that has meant the SNP now appear ready to stop undermining the project and to make sure it gets built, although I'll need to see their actual votes tomorrow before I believe it.

Across Europe cities the size of Edinburgh and smaller have managed to deliver light rail, and they're seeing the benefits. In Croydon the trams led to a 30% increase in public transport usage and a 19% reduction in car journeys. This beautiful city of ours is congested and polluted, and about to face European fines for poor air quality.

Trams are six times better at getting people out of their cars than buses are, and if powered by renewables they can be virtually zero-carbon, but the real benefits come with a full network across a city, not just a single line. The tragedy of a nearly a decade of mismanagement will be followed, assuming this line is completed, by another tragedy - that it will be almost impossible to extend the network to Leith and Newhaven, and out to Little France, as originally envisaged.

Perhaps if the Council had gone for the cheaper track system we might already be laying those next lines as the first line hummed with sleek efficient trams. Wouldn't that have been something?

Alison Johnstone is a Green MSP for Lothian, and the Green councillor for Meadows/Morningside.

More Tram Lines:

Alan Rudland: The lunatics have taken over the Asylum

Tom Parnell: The tram must continue beyond St Andrew Square

Dr Peter Mathews: The love of solutions

Charlotte Encombe: Two million is not enough to repair the tram damage in Leith