More than half young adults (56%) expect to have to wait until they are over 70 to claim the state pension.

Some 30% believe the state pension will not be there for them "at all" and 50% fear the state pension will be smaller than it is today, according to the survey for mutual Royal London.

Nearly four in 10 (37%) expect the criteria for eligibility for the state pension will change by the time they retire, potentially adversely.

The survey reveals growing young adults' growing disenchantment with the state pension which, under current rules, should pay them a state pension from age 68. Despite this many fear it will be two years later before they get their state pension.

The survey also found significant ignorance about the state pension with 74% of those surveyed unaware that receiving the full state pension currently requires 35 years of national insurance contributions or credits. 

Royal London says that the absence of generous employer-sponsored final salary schemes also means that financial security in retirement is increasingly in their own hands. Many are also waiting longer to reach key life stages such as buying a home, making retirement planner harder.

The provider said that for those relying solely on the state pension they need to be aware that at the current level of around £9,600 a year will only stretch to essential needs. It also falls short of the ‘minimum level’ of retirement income for an individual of £10,900 a year set out by the Pensions and Lifetime Savings Association’s retirement living standards. The standards class an annual income of £20,800 a year as necessary for a ‘moderate’ lifestyle.

Improving life expectancy also means that those in their twenties are likely to live longer and therefore spend longer in retirement than previous generations, says Royal London. 

Clare Moffat, pensions expert at Royal London, said: “For workers in their twenties, retirement is likely to be one of the last things on their mind with more pressing financial priorities like the cost-of-living crisis and paying bills, saving for a house or even a car, occupying their thoughts. 

“But concerns about when and how much state pension will be available might lead to an expectation that they’ll need to self-fund a greater portion of their retirement. Future financial security is likely to mean working for longer than previous generations and also saving more.

“The good news is that there’s a long-time horizon in which to not only develop positive savings habits but benefit from growth through compound interest.”

• Royal London commissioned a survey by Opinium taking place between 6 - 10 June with a sample of 4,000 nationally representative UK adults, including 462 adults in their 20s.