Lewisham Council bought 144,000 disposable plastic cups in the 12 months ending March.
The figures have been labelled “hypocritical” by Lewisham and Greenwich London Assembly candidate for the Conservatives, Charlie Davis, since the authority last November moved a motion to ban single use plastics and in February declared a climate emergency.
The cups were bought to stock Laurence House, the Town Hall, Civic Suite and Eros House.
The declaration came a month before the FOI period ended.
But Mr Davis said the authority was not moving as quickly as others to change its practices, such as Greenwich Council, which has pledged to remove single use plastics from its buildings by 2020.
Councillor Sophie McGeevor said the council had already made a commitment to end the use of single and short term use plastic in council buildings, offices, schools and nurseries by May 2022.
But the cabinet member for environment and transport said the council had stopped restocking the cups, but much more needed to be done.