The age in which people can claim their state pension in the UK is to rise to 68 from 2037, seven years earlier than previously announced, according to UK ministers.
This will affect people born between 6 April 1970 and 5 April 1978.
The change was proposed by the Cridland report, and announced in the Commons by the Secretary of State for Work and Pensions, David Gauke MP.
"As life expectancy continues to rise and the number of people in receipt of state pension increases, we need to ensure that we have a fair and sustainable system that is reflective of modern life and protected for future generations," he said.
The move comes after a report from University College London said life expectancy rates were more static after years of increases.
Health inequalities expert Sir Michael Marmot said the slowing of improvements in life expectancy was "historically highly unusual" and suggested austerity may be a factor.
Caroline Abrahams, charity director at Age UK said the announcement from the government was "astonishing".
"In bringing forward a rise in the state pension age by seven years, the government is picking the pockets of everyone in their late forties and younger, despite there being no objective case in Age UK's view to support it at this point in time," she said.
Commenting, Kenneth Gibson said:
“The SNP fundamentally disagrees with the UK Government’s decision to raise the state pension age to 68. This move will bring in changes seven years earlier than previously indicated, forcing 600,000 Scots to wait longer to access their entitlement, should they reach that age.
“Improvements in medical science mean people are living longer but many live with multiple long-term conditions, often starting in the 60s. In some communities, life expectancy is hot increasing and austerity must, as experts, such as Sir Michael Marmot, point out, must be a factor.
"This is particularly worrying given some parts of Scotland have low life expectancy due to historic and deeply-ingrained public health challenges."