It's like the old days again this week, with the talk of assignation statements and orders not to mention that old favourite, the New Roads and Streetworks Act 1991.

The reason is that the film being premiered in the Glasgow Film Theatre on Sunday night has that grand old man of dissent, Tony Benn, indicating that he leaked important documents to the Skye Bridge campaigners almost 17 years ago.

It is a year since this blog last droned on about that bridge, and every attempt will be made to limit it to an annual event. But it is difficult to resist, having spent well over a decade covering the story for many years before the tolls campaign.

The new cinema feature-length version of the film, is half an hour longer than the version shown on BBC Alba last year and has a fine musical soundtrack.

It includes interviews with Tony Benn, who had been approached by members of the Skye and Kyle Against Tolls (Skat) who visited him at Westminster.

According to a letter from the House of Commons authorities, the documents he was given were "The Assignation Statement and Regulations", which he apparently promptly forwarded northwards, although when the Herald talked to him this week he was unclear about the details.

But the official 'Assignation Statement' certainly was important. It was to become central to the 10 year Skat campaign.

The New Roads and Streetworks Act of 1991 had given the Secretary of State the right to collect tolls, but to assign this right to a third party such as the Skye Bridge Company a toll order and a statutory licence called an assignation statement was required.

But the document he leaked to the campaigners had no date and no signature.

Professor Black of Edinburgh University's law faculty said it was no more than seven pages of type, and did not entitle anyone to collect tolls.

It was presented in evidence in an appeal at the High Court but in his ruling, refusing Robbie the Pict's appeal in December 1999, Lord Sutherland made no attempt to explain why such a document was permissible in law .

At the time, Professor Black, who was always very generous with his time and scholarship, said this meant that his lordship had not ruled on the matter.

In 2005 correspondence between the Crown Office and the Procurator Fiscal in Dingwall, earmarked to remain secret for 75 years, was released to The Herald under the Freedom of Information Act (FOI). It showed that the Crown Office was aware that the legal paperwork was incomplete for the Skye Bridge prosecutions.

The Crown Office wrote on November 6, 1995 underlining how crucial the assignation statement would be in the prosecution of campaigners refusing to pay: "It will certainly be necessary to establish the right of the Skye Bridge Company to collect the toll presumably as the secretary of state's assignee."

However, in a letter dated November 27, the Crown Office conceded: "The assignation statement does not appear to be a final document."

Again Professor Black said these letters showed the Crown Office clearly recognised that the assignation statement was an uncompleted draft. "And I have to say that I've never understood how any judge could think otherwise. So much for the accused having the benefit of any doubt."

Indeed!

Some 130 people were convicted for refusing to pay without reasonable excuse. However, most had thought the company not being able to prove a clear legal right to charge the toll in the first place, was a pretty reasonable reason to withhold payment.

Several hundred others were charged but let off. Most of those convicted have yet to pay their fines, and for some strange reason they were never pursued.

The Crown Office has always stuck to the line that both criminal and civil courts were satisfied that the Skye Bridge Company was entitled to collect tolls.

But after all these years, that well worn phrase about the necessity of justice not just being done but being seen to be done, echoes still.

In December 2004 the tolls were scrapped by the then Scottish Executive. It bought out the contract from Skye Bridge Ltd (SBL), the consortium headed by Bank of America, for £27 million.

Between them, the toll and tax payer paid over £70m for the bridge. So did the campaign win?

David Hingston, the former procurator fiscal in Dingwall who admits the workload from the Skye Bridge campaign contributed to him having a nervous breakdown, is clear in the film: "It has to be said that the Skye Bridge protest succeeded. I have no doubt whatsoever that had they not made a protest, we would still be paying to cross that bridge at whatever inflated rate Miller was demanding from the public."