According to research from AXA, if these 1.5 million defined-contribution scheme members stop contributing for two years it will cost pension funds £34.97 billion.
The pensions provider has calculated a 35-year-old man could lose £28,700 from his retirement fund by not contributing over two years.
Over half (53%) of those intending to take a pensions break said they were doing to offset the rising cost living or to clear debts and 13% blamed mortgage repayments.
Steve Folkard, head of pensions and savings policy at AXA, said: "Taking a pension break should be a last resort because of the long-term repercussions.
"Planning for retirement isn't just something a 50-year-old should do. These calculations prove even people in their 20s will feel the effects of cutting their pension contributions. Final-salary pensions aren't just available to many people now and we all have to realise quality of life in retirement is affected by actions now."
One in 12 to stop pension contributions
One and a half million (one in 12) pension holders are on the brink of halting pension contributions.
