The Raj Thackeray-led Maharashtra Navnirman Sena (MNS) decided to abstain from voting in the Presidential elections, polling for which began at the Vidhan Bhawan on Thursday morning.
The party had not declared its support for either candidate in the run-up to the polls.
Congress in Maharashtra had made efforts to convince the Raj Thackeray-led party to back UPA nominee Pranab Mukherjee for the presidential poll.
Chief Minister Prithviraj Chavan is understood to have phoned Thackeray, seeking the support of MNS, which has 12 members in the 288-member Legislative Assembly.
During his visit to Mumbai earlier this month, NDA-backed presidential candidate PA Sangma had also sought Raj Thackeray's support.
Polling is being held at the Central Hall, on the fourth floor of Vidhan Bhawan in south Mumbai.