A total of six million homes could be at risk, while nearly 60% of Brits would rely on savings or their partner to cover mortgage costs if they were unable to work - despite most homeowners having less than £10,000 in savings.
London has the lowest take up of protection in the UK as just a third (34%) hold any kind of insurance, leaving 775,000 homes at risk.
Protection is most popular with Northern Irish residents where 62% have protection.
Life insurance is the most popular form, as two in five (38%) mortgage payers hold a policy, while 14% have critical illness cover and 7% have income protection.
Steve Payne, managing director of UK protection at Friends Life, said: “To find that six million homes are at risk because the owners have no financial safety net protecting them is almost unbelievable.
“Buying a house is the biggest investment most people will ever make and it’s hard to comprehend why people wouldn’t want to safeguard that.
“It has never been more important for people to be getting advice about protection insurance. Property prices are continuing to rise so a home as an investment is getting more valuable – another reason why protecting it is so important.
"With the average house price in London now over £450,000 property in the Capital is a huge investment. That figure is likely to rise further, yet Londoners do least to protect their greatest asset.”