Under current plans, owners of properties valued at more than £2 million will be hit with a surcharge of at least £2,500 from 2028.
Richmond Council says this unfairly penalises residents who have lived in their homes for decades and contributed to their community.
The authority says property prices have increased while incomes and personal circumstances have stayed largely the same or even declined.
It is estimated that around 5,730 properties in the borough would be impacted by the proposals.
The government has launched a consultation on the new High Value Council Tax Surcharge.
It says the move, announced at Budget 2025, will ensure those with the 1% most valuable properties pay their fair share.
Councillor Jim Millard, Deputy Leader and Lead Member for Finance, added the Council is also concerned about a deferral mechanism included in the proposals, where residents who struggle to make the payment could secure the charge against their home.
He said: “The proposed deferral scheme may help some households postpone payment, but for older residents on fixed incomes and disabled people living in adapted homes, it could still mean a growing debt secured against their property.
“We want the government to review the proposed income and capital thresholds for deferral. National thresholds may not properly reflect the reality of living costs in London, particularly for households on modest or fixed incomes.
“Before any thresholds are finalised, ministers should carry out detailed, borough-level analysis to understand the likely impact on older residents, disabled residents and others who may struggle to pay.”
Richmond Council says it will continue to monitor developments on the High Value Council Tax Surcharge closely and ensure residents are informed.
