Gandhi did not sign the pact. [contrarian]
On 24 September 1932, Ambedkar gave in and signed the Poona Pact as the principal signatory on behalf of the Depressed Classes, while the right-wing Hindu Mahasabha leader, Pandit Madan Mohan Malaviya, represented Gandhi and the Hindus. Gandhi did not sign the pact.
Ambedkar, B R, Annihilation of Caste_ The …, loc. 1311