Lamb and mutton workers at Wairoa's Affco meat plant will be laid off on Monday, possibly for as long as five months. Union representatives said between 200 and 300 day-shift employees at the plant would be laid off for failing to increase their workload without any offer of extra pay. Thatcomes only weeks after night-shift workers were laid off for failing to meet increased targets. Affco said it could not comment on the issue as it was an internal matter. In a letter to employees earlier this month the company said margins were too small to support production on "any chain that is inefficient". The seasonal nature of the meat industry meant layoffs - normally between five and 12 weeks - were expected if stock levels were low, Eric Mischefski from the New Zealand Meat Workers' Union said. But Affco had not hidden the fact the layoffs were due to a quota increase. "They said the plant was uncompetitive and the workers had to do the extra work for nothing," he said. The company said if the target could not be reached it would have no choice but to move stock to a more efficient plant elsewhere. A letter sent to the union and workers on Wednesday said stock had already been sent out of the region "because of the position the union took in relation to the night shift increasing the chain speed". The union claims issuing the ultimatum over production speed was altering the terms of the workers' employment agreement. "They [Affco] want to negotiate the terms and conditions of the employment with the threat of no work," Mr Mischefski said. The union would consider taking Affco to the Employment Relations Tribunal. Mr Mischefski said the Wairoa plant, which at the peak of the season could employ around 700 staff, had never had a problem with quality or speed before. Affco yesterday reported a net after-tax profit of $15.9 million for the six months to March 31.