Under pressure from the opposition, Quebec's government is debating changes to a tax credit for seniors.

The Coalition Avenir Quebec has been calling the government of being insensitive and disconnected from the reality of being retired in Quebec.

Party leader Francois Legault and Treasury Board critic Eric Caire say the problem is the government's plan to change a timeline for tax credits.

Finance Minister Carlos Leitao's plan is to change the age of eligibility for a tax credit from age 65 to age 70, but do it over five years.

They said it would cost people up to $500 per year.

"Can the premier finally show some sensitivity to the reality of being retired," said Legault.

Caire said the changes were being made because people wouldn't notice.

"They clearly attack vulnerable people, vulnerable seniors," said Caire.

"They tax the seniors - because it's a kind of tax for me, for us - and before taxing anyone, make sure that you manage properly the money you have in your pocket right now."

Finance Minister Carlos Leitao disagreed with how the CAQ assessed the situation.

"That is simply not true. No one has seen any payment cut. Nothing has been cut. Those that were receiving, those who were eligible to receive the tax credit will continue to receive the tax credit," said Leitao.

He said it's necessary because the average life span is longer than ever before -- and much longer then when the tax credits were first introduced.

"In the 1970s the life expectancy of a 65-year-old was about five years. Today the life expectancy of a 65-year-old is at least 15 years, until age 80. So things have changed and we have to adjust," said Leitao.

During Question Period Premier Philippe Couillard said the proposal is not yet set in stone.

"This measure is not yet in force, which gives us time to evaluate it ," said Couillard.

The final version of the tax credit alteration should appear in the budget, due next month.