Secretary of state for work and pensions Iain Duncan Smith has defended the independent review that his department has launched into state pension age.
Responding to an urgent question from the shadow secretary of state for work and pensions Owen Smith, he added that changes to the state pension age could need to be taken to make pensions more sustainable.
But some have warned that millions more working-age people may have to wait until their 70s to retire after the government launched an official review of the state pension age.
"Can [Duncan Smith] confirm the government is consider of speeding up subsequent rises, with increases to 69 or 70 for people currently in their mid-40s," the shadow minister said.
He added: "Does he agree with his pensions colleague in the Lords that in the light of his reforms the state pension age should not be considered the retirement age?"
Speaking to MPs, Duncan Smith responded by saying that it was Labour that first increased the state pension age, but had failed to launch an independent review.
He again confirmed that Sir John Cridland will lead a review, which is the first for the UK. Duncan Smith encouraged other MPs to raise issues with Cridland that they think pertinent to the review.
The review will evaluate what effects aspects like changing life expectancy will have on the department's ability to provide state pension and to be able continue to provide for future generations in a sustainable manner.
If a matter of public importance has arises, which an MP believes requires an immediate answer from a government minister, they can apply to the Speaker of the House to put forward such a question.