Savers are calling for an end to what they describe as "totally unfair" state pension changes that could leave some almost £18,000 worse off in retirement.
Campaigners say many people have spent their entire working lives preparing their finances based on the current rules.
Figures from wealth managers Rathbones suggest workers aged 51 to 53 could miss out on up to £17,774 in payments if the change to the state pension goes ahead.
The petition, started by Steven Hillyer, states: "Leave the state pension qualifying age as it stands at 67, for those born prior to 1977, and have planned their retirement accordingly."
It added: "We think it is already far enough off and many people simply cannot work longer. We think they have paid in their dues and it is totally unfair to move their entitlement further away at a late stage in their lives."
Current legislation sets the state pension age to reach 67 by 2028, with the rise to 68 scheduled for between 2044 and 2046.
However the proposed acceleration would shift retirement timelines dramatically for workers who have structured their financial planning around existing schedules.
Chancellor Rachel Reeves has defended examining the qualifying age, telling reporters in London: "As life expectancy increases it is right to look at the state pension age to ensure that the state pension is sustainable and affordable for generations to come."
Pension crisis looms | GETTYShe added: "That's why we have asked a very experienced set of experts to look at all the evidence."
Rachel Vahey, head of public policy at AJ Bell, noted that whilst an increase from 66 to 67 is already scheduled between 2026 and 2028, subsequent changes remain uncertain.
"There is also an increase to age 68 pencilled in for 2046, but a faster increase is definitely on the cards," she said, adding that previous reviews have recommended acceleration but Governments have avoided decisive action.
According to investment firm Rathbones, bringing forward the state pension age rise to 68 could mean it takes effect between 2039 and 2041, instead of the current 2044 to 2046 timetable.
Pensioners are concerned about the Government's handling of their pensions | GETTY/GB NEWSThat would see people aged 51 to 53 lose an entire year of pension payments, a major blow for those who have planned their retirement around the existing rules.
Rathbones estimates a 51-year-old could miss out on £17,774 if the change goes ahead, while 52-year-olds could lose £17,340 and 53-year-olds £16,918.
These figures are based on the current full state pension rate of £230.25 a week, £11,973 a year, and assume the triple lock guarantee stays in place.
Britons are concerned about the rise in the state pension age | GETTYIf the triple lock were scrapped, the losses would still be steep. A 51-year-old would forfeit £16,436, while 52-year-olds would lose £16,114 and 53-year-olds £15,798.
Rebecca Williams, divisional lead of financial planning at Rathbones, said: "With longevity increasing and population pressures mounting, future generations appear set to face a less generous state pension regime than that enjoyed by many of today's retirees.
"The situation appears particularly precarious for those in their early 50s who face a real prospect of missing out."
The petition requires 10,000 signatures to secure a Government response and 100,000 to trigger a parliamentary debate.