People aged 60 and over can get free travel on TfL, including buses, underground and National Rail services in London using the 60+ Oyster card until they qualify for the Freedom Pass at state pension age.

While one petition is urging for it to extend across the country, some experts are now calling for it to be scrapped and reworked.

New figures have shown the 60+ Oyster Card will cost £135million this year, a figure which will only climb as more of the UK's ageing population becomes eligible. In comparison, people jumping through the barriers on the Underground cost TfL around £130million.

The UK's rapidly ageing population has seen many benefits and support adjusted over recent years to ensure the welfare system supports the most vulnerable without becoming completely unsustainable.

Reem Ibrahim, of the Institute of Economic Affairs, is suggesting that free travel should be the next over 60 benefit up for a revamp in light of the current economic climate.

She told the Telegraph: "It is difficult to justify a system where the wealthiest age group in the country is having their travel funded by taxpayers.

"The 60+ Oyster card and Freedom Pass schemes are financially unsustainable, and are not targeted to those genuinely in need of support. We urgently need a more targeted approach, rather than entrenching an unfair and costly system."

Liz Emerson, chief executive of the Intergenerational Foundation, added: "It's a perfect example of intergenerational unfairness at work with younger workers having to subsidise their older colleagues' free travel to work."

The 60+ Oyster card is expected to cost up to £185million by 2027.

On top of this, the cost of funding the Freedom Pass is expected to hit £498million by the end of the decade.

TfL figures show that 60% of people with a 50+ Oyster card are still in paid employment and one in five use the bus pass to get to or from work.

A spokesman for Transport for London told the outlet: "Both the Mayor and TfL are committed to making public transport in London as accessible, convenient, and affordable as possible.

"We regularly review our range of concessions to ensure that they continue to benefit Londoners, while also remaining affordable for TfL to operate."

On the other hand, a petition to extend free bus travel for people over the age of 60 in England had garnered over 96,000 signatures. At 100,000 signatures, it will be considered for debate in Parliament.