(Reuters) -Telecom operator AT&T (NYSE:) has presented the Communications Workers of America’s bargaining committee with its final offer, the union said on Thursday, adding that the proposal did not meet its expectations.

The CWA union said the proposal was made on Wednesday and it made a counteroffer later in the day.

“What the company is not telling our members and the public is that their healthcare proposal raises the upfront cost for our members, especially those with family coverage. We have made it clear to the company from the start that raising our members’ cost share percentage is unacceptable,” the union said.

More than 17,000 employees at the company including technicians and customer service representatives, and others who install, maintain and support AT&T’s residential and business wireline telecommunications network went on strike last month to protest unfair labor practices.

“We have made a strong final offer to the CWA District 3 in the Southeast. We believe that this offer, if accepted, would provide our employees with competitive market-based pay that exceeds projected inflation,” AT&T Chief Operating Officer Jeff McElfresh told Reuters in a statement.

The company is also offering to increase its financial contributions to employee healthcare and wellness by up to 25% per year, McElfresh added.

The union informed AT&T and the Federal Mediation and Conciliation Service on Monday that it would no longer be a part of the mediation process, calling it another “delaying tactic”.