POLLUTION COULD go undetected, contamination unchecked and toxic waste unscrutinised in the most serious crisis to be faced by Scotland's official environment watchdog.

Tomorrow, staff at the Scottish Environment Protection Agency (Sepa) are due to begin an unprecedented campaign of industrial action which could see the environment suffer as incidents occurring outside office hours are not covered.

Concerned about the risks, Sepa's management has made a last-minute plea for exemptions to the industrial action. This is due to be discussed at a meeting with the trade union, Unison, tomorrow morning.

Although the dispute has been triggered by grievances over a proposed new pay and grading system, it reflects long-simmering differences between staff and senior management over the style and substance of leadership within Sepa.

According to Unison, staff last week voted by an 88% majority to take industrial action short of an all-out strike. In an earlier ballot, 93% backed a motion of no confidence in management.

"These are large margins for a workforce ballot," said the chair of Sepa's Unison branch, Alan Fleming. "There is an underlying problem of lack of trust in management."

Unison, which represents 800 of Sepa's 1300 employees, is instructing members not to co-operate with managers by refusing to cover pollution incidents and floods out-of-hours. Staff will also be expected not to enter vital data on computers, and not to respond to inquiries from ministers.

The main aim was to hurt Sepa, Fleming said, but he accepted that the environment could be put at risk in the process. "We are trying to limit the damage to the organisation but it's impossible to avoid knock-on effects," he told the Sunday Herald.

He blamed Sepa's failure to respond to staff's concerns for any problems that might arise. "Our members have been forced into this action by a completely intransigent management," he said.

The cause of the industrial action was an attempt by managers to force through a new pay scheme, which Unison says will cause some staff to lose thousands of pounds a year.

In February all staff were offered new contracts of employment, but 43% refused to take them up. As a result, managers issued dismissal notices to more than 500 staff, accompanied by offers to re-engage them on new terms.

"No-one is being made redundant, but this remains a difficult and unfortunate step for Sepa to take," said an internal memo from the corporate management team. "We deeply regret having to take this action."

Sepa said on Friday there were still 489 staff who had failed to take up the new offers of employment. If they haven't done so by the end of this month, their dismissals will take effect.

The nature and extent of this week's industrial action is not yet clear, according to Sepa. But managers have put contingency plans in place to protect essential and emergency services.

Sepa environmental protection director, Colin Bayes, said: "I am confident that Sepa will continue to provide effective environmental protection during this industrial action, giving priority to significant or major environmental incidents and to our duties under the Civil Contingencies Act."

But environmental groups are worried. "This may impact on Sepa's ability to respond to the threat of pollution or deal with a pollution incident," said the acting director of WWF Scotland, Dr Dan Barlow. "We would urge Sepa to resolve this promptly."

Sepa staff who have contacted the Sunday Herald insist that the risks to the environment are real. Senior specialists responsible for monitoring potentially dangerous plants at Grangemouth, Dounreay, Hunterston and Longannet are said to be deeply disillusioned.

Insiders accused management of being "weak, indecisive and out-of- touch" and of promoting an "appalling cack-handed, amateurish and inconsistent job evaluation". Unison, however, was also condemned for a "truly abysmal performance from start to finish".