Anglian Water has denied it is “seeking industrial unrest” in a dispute over workers pensions.

Britain’s largest union, Unite, made the claim after the water company declined an offer to take talks over the closure of its final salary pension scheme to conciliation service Acas.

Unite says thousands of workers at Anglian Water are affected by the pension scheme’s proposed closure, as well proposed changes to a separate existing defined contribution scheme. It says some employees could see their pension pot reduced by up to £100,000. Unite said that, along with the GMB and Unison unions, it held “a last ditch meeting” with Anglian Water chief executive Peter Simpson on Thursday but the dispute remains unresolved.

Anglian Water has responded by saying that it doesn’t believe the union’s position is backed by workers and that, in contrast, over 2,000 people took part in its consultation on the creation of the new pension scheme.

It says the new arrangements offer an “equitable, fair and financially sustainable pension” for employees and “the majority of employees are likely to be just as well off, and could be better off.”

Anglian Water operates more than 1,200 water and water recycling treatment works across East Anglia and up the east coast.

Unite regional officer Adam Oakes said the changes would hit workers at a time when the water company paid out just over £320 million in dividends to shareholders in 2016/17.

He added: “Rather than entering into talks, management is trying to railroad through pension changes. The offer of a derisory £600 in compensation, at a time when Anglian Water is paying out millions to shareholders, is an insult to a loyal workforce.”

In a statement, a spokesperson for Anglian Water responded: “There is no reason to go to ACAS while the unions refuse to be open about what support there is for their position, if any.

“We simply do not believe the Unions have support for their position. They’ve refused to share turnout numbers and have not even given employees the option to accept the generous deal we’ve put on the table. Our obligation is to provide an equitable, fair and financially sustainable pension for all our employees, and a bill that is affordable for customers.

“This is something that simply wouldn’t be possible given the escalating costs of our old Defined Benefit scheme.”