Across all households, just over half of usual spending covers items such as food and housing costs.
But renters spend 61 per cent of their weekly budget on essentials, which cannot be cut back, the statistics authority found.
This is mostly because of housing costs, which account for 28 per cent of budgets for renting households and 21 per cent for homeowners.
As a result, tenants’ ability to save in lockdown may be more limited, even though overall a fifth of usual household spending has not been possible during this time.
Franz Doerr, chief executive of flatfair, said: “Today’s figures from the Office of National Statistics do not come as a great surprise, but underline the threat that coronavirus poses to the rental market.
“Renters do not have as much breathing room to cut back on spending, leaving them vulnerable to economic shocks.
“While it is positive that the government has further extended the moratorium on evictions, they cannot just keep kicking the can down the road.
“Action needs to be taken to support tenants and landlords alike to communicate, and ensure that a fair and equitable solution is found in the unfortunate cases where a tenant cannot pay their rent.”