In London, where the cost of living is comparatively higher, this figure more than doubles from 18% to 49%, the report from Post Office Money Savings found.

It said UK parents and grandparents collectively spent almost £18bn supporting their adult offspring – that’s an average of £900 each.

For those who have provided financial support in the past five years, 39% funded day-to-day expenses, 32% contributed towards holidays and 24% helped pay for household bills.

Just under a fifth (17%) helped pay off debts.

More than half (55%) used savings to provide financial support, while 14% used a credit card.

The research revealed some parents go to worrying lengths to financially ‘prop up’ younger family members. Some 30% sacrificed putting money into their own savings, while 7% forfeited making pension contributions.

Seven per cent even skipped paying their own household bills to ensure they could support adult children and grandchildren.

Henk Van Hulle of Post Office Money Savings, said: “Many of today’s millennials face an uphill struggle in establishing themselves as financially independent; soaring house prices, the expectation they should be saving for retirement, and meeting day-to-day living costs can add up to significant challenges when it comes to managing their finances.”

“We understand that parents feel it is their duty to provide financial support for their struggling children, but it’s also important that they don’t sacrifice their own financial stability.”