The Progressive Conservatives are taking renewed aim at “gold-plated” pensions for teachers, civil servants and other public sector workers as Ontario struggles to eliminate an $11.9 billion deficit.

Ontario needs to negotiate new deals for pensions with public sector unions, raising retirement ages and making the plans more in line with what’s available to private sector workers — but only for new hires, PC Leader Tim Hudak said Monday.

That could mean a move from “defined benefit” plans where retirement payouts are set in advance to “defined contribution” plans in which benefits depend on the finances of the pension plan, which the Conservatives first proposed in a policy paper last November.

“These gold-standard pensions are not affordable,” he told reporters as all three parties at Queen’s Park jockey for position with the possibility of spring election looming if Premier Kathleen Wynne’s first budget does not pass.

Legislating such pension changes would be a last resort if negotiations fail, said Hudak, who brushed aside questions about potential strikes by teachers and other public sector workers over the issue.

The pensions are a “ticking time bomb” with an unfunded liability as high as $100 billion by some estimates, added Hudak, who did not specify how much could be saved by moving new government hires to less expensive pension plans.

He noted a major report by former TD Bank chief economist Don Drummond last year on putting public finances on a sustainable footing found that the government’s pension costs for unionized workers will rise to $4.2 billion in 2017 from $3 billion last year.

Wynne accused Hudak of “driving a wedge” between public and private-sector workers for political gain and said the government has been trying to clamp down on rising pension costs.

“We’re working to make sure pension plans are viable.”