The temperature of in-council fighting can be gauged by two letters How Wattersgate hit boiling point

Both were from branch officials of the public service union Unison. They reveal the improbable origins of part of the case that Mr Watters, with the backing of the same officials, has threatened to take to the Court of Session with an interim interdict that is expected to be sought today.

Branch chairperson Tom Rainey wrote to ''put on record'' a chance meeting he had with Councillor James McCallum, convener of the information services committee, in Dumbarton High Street on an unspecified Saturday in November the previous year. Mr Rainey had just returned from a Celtic football game. He had entered a shop to buy a lottery ticket.

These details of Mr Rainey's life are puzzling inclusions in a letter apparently written and received with the utmost gravity, but the point he is at pains to communicate is that Councillor McCallum approached him inside the shop.

Mr Rainey reveals that he had been ''extremely critical and unhappy'' about the role of depute chief executive, Mr Ian Leitch, in the council's ''targeting and pressuring'' of its employees who were in arrears with council tax. Councillor McCallum allegedly asked Mr Rainey if any employee would be willing to make any complaint that could be substantiated against Mr Leitch. It would be ''fully investigated''. Mr Rainey said he would think about it.

Two months later, apparently, he had concluded that Councillor McCallum was ''ill disposed'' to Mr Leitch, a member of the union. The second letter, sent the same day from the same Unison office, was from branch secretary Denise Lafferty. She related a separate incident which had also occurred in November of the previous year. She had also been complaining ''about the attitude of Mr Leitch towards employees over the council tax arrears issue''. The branch office was ''inundated with complaints''. She raised the issue with Councillor Andrew White, leader of the council. He responded: ''Give us a complaint and we'll do something about it.''

Two months later, this ''innocuous'' remark had assumed ''a more sinister connotation'' in Ms McLafferty's mind. She wished to put her ''concerns on record for future reference, if required''.

Recognising a significance that had only belatedly stirred his vigilant correspondents to act on the same day, Mr Watters felt under an obligation to raise matters to a higher authority. He wrote to Provost Pat O'Neill six days later. He opened: ''This is the most difficult letter I have had to write.'' It was five pages. Mr Rainey's letter was appended. The Dumbarton High Street incident was contained as one of 26 points made in a catalogue of complaints against councillors McCallum and White.

Mr Watters wrote that a series of events, from June 1997 onwards, was connected. He alleged a ''systematic attempt'' to get rid of either himself or Mr Leitch, or both of them.

The continuing escalation of this complaint has been a subject of morbid fascination and bewilderment. Each development towards the giddy heights of the Court of Session has been assiduously leaked to this newspaper, and some of Mr Watters's colleagues are now questioning his ability to remain in local government.

Recognising where it all went seriously wrong is easier than establishing where it really began. From the moment that the Labour Party expressed profound scepticism over the substance of several of Mr Watters's allegations it must have been obvious that this was not going to be treated as another hysterical sleaze exposure, after Glasgow and Renfrewshire.

SNP demands for suspension of the two councillors were rejected. The West Dunbartonshire Labour group called for an independent investigation to be set up by a suitably qualified person appointed by Cosla.

Cosla's objectivity was questioned by Ms McLafferty. Her letter, on Unison headed notepaper, was suspected by councillors, members of the directorate and Labour Party officials, to have been produced on the same word processor, using the same layout and font, as correspondence produced from the office of Mr Leitch.

Throughout the dispute, which has seen the postponement of a three-man independent investigation and the likely postponement of a grievance procedure initiated by Mr Watters which was due to start tomorrow, the figure of his deputy, Mr Leitch, has been kept in low profile. Few imagine this to be without significance.

If, as the Unison letters of January 8 appeared to identify, Mr Leitch is at the true heart of a growing antagonism in West Dunbartonshire, it will not have been the first time that Mr Watters has demonstrated support for Mr Leitch. There were ''jobs for the boys'' allegations in July 1995 when Mr Leitch was appointed to the deputy chief executive post on the personal recommendation of Mr Watters. The job was not advertised.

Mr Leitch's professional relationship with Mr Watters dates back to the late 1970s when they were lawyers in the Castlemilk Community Law Centre.

Then their roles were reversed. Mr Leitch, five years the senior of the two, was director.

He seemed destined for a big career in politics. At the age of 21 he was elected to represent the Bellsmyre ward on Dumbarton Town Council.

Narrowly missing out (by four votes, he reminds people) to Donald Dewar as Labour candidate for the Garscadden by-election in 1978, he was adopted as Labour candidate for Caithness and Sutherland in 1981, only to stand down to chair the Scottish Campaign Against Trident. His next opportunity for a parliamentary career came in 1985, but he was eventually defeated by John McFall as prospective Labour candidate in the Dumbarton constituency.

One year later he was defeated by two votes for leadership of the Scottish CND.

This setback led indirectly to the end of his 20-year career in council politics when the 1990 Local Government and Housing Act presented him with a choice between his seat on Dumbarton District Council or his job as administrative and legal officer with Clydebank District.

Five years later he was surprisingly beaten, again in a narrow vote, for the #73,000 chief executive's post with West Dunbartonshire Council by his former protege, Michael Watters. The terse explanation for Mr Leitch's evident run of bad luck with votes is that to win them you need friends. Throughout his career his capacity to make enemies has been noted. Opponents testify to his intelligence and political astuteness, but also regard him as arrogant, confrontational and aggressive.

The power behind the throne was always seen as Mr Leitch.

Their tenure ran smoothly until the election on June 3 of last year of Councillor White as Labour group leader on the council.

Mr Leitch must have recognised something of his youthful self in the emergence of Councillor White, at 28 the youngest leader in a Scottish council.

The style was different, as Mr Leitch must have quickly discovered when he attempted to take what has been described as an almost paternal interest in ''the boy''. They played badminton a few times. Easy going and popular, Mr White reveals a self-confidence in his own ideas of doing things.

His background was in Labour Club politics at Glasgow University where he built enough consensus among opponents to be voted into a sabbatical vice-presidency on the SRC. He built up a solid reputation for integrity.

He met his future wife, Margaret Mary, taking a group of disabled students to Lourdes. They were married this month. The honeymoon, like most of the attempts to resolve the West Dunbartonshire dispute, has had to be postponed.

It would not have been difficult for as experienced a political hand as Mr Leitch to realise the vulnerability of his own position when Councillor White began taking a close interest in the management structures of councils of comparable scale to West Dunbartonshire. Out of 32 Scottish authorities, Councillor White identified only four others which employed a depute chief executive, and Highland and Glasgow were in process of taking steps to shed the posts.

A motion passed on December 17 by the finance committee of West Dunbartonshire targeted #300,000 savings from a management review. Mr White talked about minimised bureaucracy and a protection of front line services in a council that had faced #15m in budget cuts in the first three years of its existence.

In a council which had already streamlined its directorate to six posts, it was clear that the job of Mr Leitch was under threat. Another aspect, which has had more than one bearing on the dispute, is that in Mr Watters, Mr Leitch and head of legal and administration services, Mr Stephen Brown, the council has an unusually high quota of legally trained talent. Their combined annual cost to the council, after a 3% rise fixed this month, is #226,000.

The finance committee decision to bring in a Cosla consultancy, appointing Mr Neil McIntosh, former chief executive of Strathclyde region, to carry out the review independently, was scarcely going to allay fears. Whether this was shaping into a ''backdoor'' method of preparing the sacking of Mr Watters and Mr Leitch, as Unison claimed, or a legitimate exercise to provide the best service for taxpayers, as the Labour Party responded, the almost inevitable result was a public bloodletting. During the course of the dispute, Mr Watters attended a meeting at Cosla.

It was either designed to offer him an exit package or seek a form of conciliation, depending on what sources are consulted. Either way, it was a failure.

If, as Mr Watters claimed, Cosla advised him his position at West Dunbartonshire was untenable, there were grounds to support the view.

The entire directorate signed a letter of February 6 to Provost O'Neill to support the decision the previous day when the council agreed to set up the independent investigation into both the allegations and the ''political and managerial culture'' within the authority.

On March 4, three finance managers requested to be interviewed by the investigation on management culture and ''gross interference in the audit process''.

They will have to wait for the latest development expected in today's interim interdict against alleged bias of two of the councillors, Jim Flynn and Douglas Mills, appointed to hear the grievance against Councillors McCallum and White.

The Labour Group is determined to press on with the hearing, due to start tomorrow, after the SNP refused to nominate a councillor.

The ''Wattersgate'' affair may lead to a move to avoid a situation where a chief executive's grievance against his employers is heard by his employers.

The dispute has been a baptism of fire for Councillor White. On Thursday he will present himself for selection for the final panel of Scottish MPs which will be decided in July.

The betting is he will not be around to stand at the next council elections on May 6, 1999. If they can use delaying tactics, the best hope for Mr Watters and Mr Leitch is the long-shot gamble that the SNP gain control of West Dunbartonshire Council.