The Maine State Employees Association is suing the state for longevity pay Union members lost last year. Lawmakers eliminated longevity pay during the 2010 fiscal year in a budget-balancing move. It was restored as of last month.Longevity pay rewards state employees based on years of service. The lawsuit claims the state’s denial of the pay is a case of age discrimination and employment discrimination because it treated older workers with seniority less favorably than younger workers with less time on the job. Attorney General Janet Mills, who is defending the state, says that the workers can’t legally get back the lost pay.