FREDERICTON -- Hundreds of angry civil service retirees protested outside the New Brunswick legislature Wednesday demanding proposed pension plan revisions to be scrapped, but the finance minister says the changes are necessary to ensure the fund is solvent.

Pensioners voiced their frustration with the changes introduced by the Progressive Conservative government as it returned to the house of assembly for the first full day of the fall session.

"These guys are just going ahead and nothing they see or hear matters," said protest organizer Bonnie Hoyt Hallett.

"They need to involve us as retirees and they need to involve the people that are still working."

Police estimated more than 1,500 people took part in the protest.

The government wants to implement a shared-risk model in an effort to address a $1-billion deficit in the public service pension plan. Under the changes, unveiled in May of last year, employees would pay between 1.2 and 2.8 per cent more in premiums, while employers would see an increase ranging from 1.2 to 3.9 per cent.

Cost-of-living increases would be conditional on pension plan performance, and over the next 40 years, full pension eligibility would be moved to 65 years of age from 60. Surpluses could be used to make up for any years where cost-of-living increases have decreased, or could be used to reduce premiums.

The protesters, many carrying signs accusing the government of breaking their word, said the changes are unfair to them.

"We are paying every tax that everyone else is paying in this province, but you are throwing the rest of this on the backs of pensioners," said Glen Wilson as he confronted Finance Minister Blaine Higgs outside the legislature.

But Higgs said the current plan is not sustainable and changes must be made.

"Doing nothing is not an option," Higgs said. "We are committed to making sure it is there for the pensioners, it's there for the current employees and it's there for future employees."

Higgs said retirees would always receive at least 75 per cent of inflation for their cost-of-living increase, and when profits allow that could go up to 100 per cent.

But the retirees say their plan now guarantees the full cost-of-living increase and they want that maintained.

"We would rather not go legal, but if that's the route we have to take, we will take it," said Hallett.

"We would like to see this stopped and the reset button pushed, and we'd like government to start listening."

The government said it was pressing ahead with the changes in its throne speech Tuesday.