The Canadian Taxpayers' Federation says it's disappointed Edmonton North MP Deborah Grey has opted back into the parliamentary pension plan.

The Canadian Alliance MP had repeatedly criticized the plan as being "gold-plated" and unfair to taxpayers. But Grey recently decided to buy back a dozen years of her pension.

The taxpayers' federation has, in the past, supported Alliance policies. Spokesman Troy Lanigan says the federation commended the former Reform party and the Alliance for taking a stand against "this bilking of the taxpayer." But he says this latest move will hurt the party's credibility.

"So many Reform and Alliance MPs said, 'send us to Ottawa. We're different,'" says Lanigan. "They've proven to be no different than the Liberals."

Lanigan also says opting back into the pension plan is "a very important symbolic issue."

Grey says she decided to opt into the pension plan after learning former Reform leader Preston Manning had cancer. She says it made her realize she needed a pension in case anything happened to her or her husband.