A union representing thousands of federal government economists and translators says contract talks are at an impasse because the government isn't offering what it gave members of other large public service unions earlier this month.

The Canadian Association of Professional Employees, or CAPE, has rejected the offer to some of its 12,000 members.

Emmanuelle Tremblay is national president of CAPE. (Chloe Fedio/CBC)

The union's leadership says it's upset some of its employees aren't being offered the same raises as members of other unions, and that it isn't getting protection for members that give the government what it calls "evidence-based advice," according to a media release.

"We were simply asking that our members be protected and not be punished if they give evidence-based advice. The employer refused, and proposed a vague clause that would be linked to the code of ethics of the public service," the release states.

"... The employer demonstrated an unreasonable unwillingness to negotiate," said CAPE national president Emmanuelle Tremblay in another release.

"Not only are they offering sub-par economic increases for our members, but they are not even able to justify their salary position with hard evidence. On the other hand, we provided them with a detailed wage analysis."

CAPE said it has applied for binding conciliation to get a new deal.

In a statement sent Thursday night, a Treasury Board spokesperson wrote that the government "put forward a fair and reasonable offer to CAPE's economist group that was in line with proposals made to other groups.

"We remain committed to reaching agreements in a way that is fair and respectful, allowing us to continue to focus on delivering on our agenda of good jobs and growth for the middle class."