In an open letter to housing minister Robert Jenrick, the party has said the tax cut is worth £1.3bn to property investors.
The cash could fund the gap in local councils’ finances, Labour argued.
In the summer statement this week, Sunak axed stamp duty on homes worth up to £500,000 for all buyers until 31 March 2021.
Second homebuyers are still subject to the three per cent stamp duty surcharge.
In 2019/20 more than a third of homes bought were second properties, according to Labour.
Shadow housing minister Thangam Debbonaire said: “It is unacceptable that the chancellor tried to sneak out this huge bung to second homeowners and landlords while millions of people are desperate for support.
“He should be targeting support to those who need it, not helping people invest in buy-to-let properties and holiday homes.
“An unnecessary subsidy for second home-owners will only worsen the housing crisis by reducing the supply of homes overall.
“We need a credible plan from Tory ministers to build the homes our country needs and get people on to the housing ladder. We didn’t see that this week.”
A Treasury spokesperson said: “The housing market has been hit hard by the outbreak with 175,000 missing sales – so we are doing everything we can to get the country moving again.
“Our cut in stamp duty will help drive growth and support jobs across the housebuilding and property sectors.
“Those buying second homes or buy-to-let properties will continue to pay an additional three per cent on top of the standard SDLT rates.”