About 4,500 trees in one west London borough could be cut down in a bid to save up to £120,000 a year.
Ealing Council says the move will stop damage the roots cause to houses and pavements.
But Councillor Nigel Sumner says a promise to plant two new trees for every one cut down will prove to be even more costly.
Ealing Council says at the moment the plans are at a consultation stage and that nothing has been decided.
Cllr Sumner said: "There may be some bad trees whose roots are affecting pavements and property but I think there are only 50 or so - which is much less than 4,500."
A spokesman for the council said it spends £120,000 a year in maintenance and in paying out compensation to people who have tripped over damaged pavements and subsidence to houses.
The spokesman added: "This is tax payers money we are looking to save.
"These discussions are only proposals at this stage and no decision has been made despite claims to the contrary."