Raising Britain's state pension age to 68 years risks creating second-class citizens, the leader of Britain's biggest worker organization said Wednesday.

The British government announced on Wednesday that it is to bring forward by up to seven years the raising of the state pension age to 68.

TUC general secretary Frances O'Grady said: "In large parts of the country, the state pension age will be higher than healthy life expectancy. Low-paid workers at risk of insecurity in their working lives will now face greater insecurity in old age too."

"Rather than hiking the pension age, the government must do more for older workers who want to keep working and paying taxes. Workplaces and working patterns need to adapt to their needs, he added.

British ministers say the change is in line with continuing increases in life expectancy. The Department for Works and Pensions (DWP) said the state pension age is regularly reviewed to make sure that the pension system is affordable and fair.

But with people living longer, and spending a larger proportion of their adult life in retirement than in the past, the dates are to be amended.

Latest projections from the Office for National Statistics (ONS) show that the number of people over state pension age in Britain is expected to grow by a third between 2017 and 2042, from 12.4 million in 2017 to 16.9 million in 2042.

Under the existing law, the state pension age was due to increase to 68 between 2044 and 2046. Following a review the government announced plans to bring this timetable forward to 68 between 2037 and 2039.

A DWP spokesman said: "When the State Pension was introduced in 1948, a 65-year-old could expect to spend 13.5 years in receipt of it -- around 23 percent of their adult life. This has been increasing ever since. In 2017, a 65-year-old can now expect to live for another 22.8 years, or 33.6 percent of their adult life."

The changes mean there will be no change for people born on or before April, 1970 who will qualify for state pension when they are 67. People born between 1970 and 1978 will see the pension age rise to 68 depending on their date of birth, and people born from April 1978 will get their pension when they reach 68.

The DWP said the proposed changes need parliamentary approval.

Secretary of State for Work and Pensions David Gauke said: "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."