Alward says the provincial wing of the union was supportive of the plan to move to a shared-risk model for pensions and he doesn't know why that would change now.
"It's unfortunate that the national CUPE leadership has seen fit to come to New Brunswick and try to take over the responsibility for the files," Alward said Tuesday.
But the president of CUPE New Brunswick said decisions about pensions are being made at the local level.
Danny Legere said the shared-risk model being pushed by the provincial government was the best option for some unionized workers such as hospital staff, but not so for others who have defined benefit plans.
"Some defined benefit plans are very healthy and don't need this kind of drastic intervention," Legere said.
He said the union is hiring an actuary to study the proposed pension changes and will consider legal action if needed to block them.
New Brunswick's public service pension plan has a $1-billion deficit and Finance Minister Blaine Higgs says it is not sustainable.
Under the changes, employees and employers would pay higher premiums and cost-of-living increases would be conditional on pension plan performance.
Over the next 40 years, full pension eligibility would be moved to 65 years of age from 60.
"We will be moving forward," Alward said. "It is that important for our current employees and future employees, for pensioners and for taxpayers, so that we can assure that the system is sustainable for the long term."
The government is expected to table legislation before Christmas to make the pension changes.