Newham Council has cancelled a grant of £661,920 for a new sports pitch in West Ham.
In the first cabinet meeting since new mayor Rokhsana Fiaz replaced long-serving Sir Robin Wales after the May elections, the council decided to review "big money decisions" made by the previous administration.
Mayor Rokhsana described the decision as "unjustifiable".
She added: "The decision by the previous administration to carelessly allocate more than half a million pounds to a project with no clear benefits for the wider community is unjustifiable.
"Any proposal agreed in future will ensure it is truly about improving the health and well being of all our residents and diverse community."