The study for investment firm Hargreaves Lansdown suggests younger people are the most likely to believe they will become millionaires.

Men are twice as likely to expect to become millionaires.

Key findings from the research:

• Almost one in four people expect to become a millionaire (23%) at some point in life
• Only 2% expect to be a millionaire by the age of 20, but one in 10 expect it sometime between 30 and 50
• A third of 18-34-year-olds expect to become millionaires before age 50 (33%)
• Men are almost twice as likely to expect to become millionaires as women (30% compared to 16%)

Opinium surveyed 2,000 UK consumers for HL in May.

HL says that to be a millionaire in 2020, people would need to have been in the top 17% of households (ONS).

Sarah Coles, head of personal finance, Hargreaves Lansdown: “Being a millionaire isn’t what it used to be. It’s still a huge amount of money, but it’s no longer an unimaginable level of wealth.

“Almost one in four of us expect to be worth a million at some stage, and for an awful lot of people, it’s not beyond the realms of possibility."

She said inflation has made it more possible to reach £1m in total wealth as the value of money has devalued. Someone with £1m in 1998 would need £1.8m now to enjoy the same spending power.

She added that while many expect to be millionaires with the average UK median wealth for an individual at £300,000 it was “far from a foregone conclusion.” However average media wealth among retired people is £489,300, making it more likely older people will have high levels of wealth.

HL research shows that the biggest chunk of wealth is held in pensions as pensions account for 42% of wealth in the UK. Some 36% of wealth is in property. About 13% of wealth is held in investments.