Mumbai,  Marking a breakthrough, Chief Minister Eknath Shinde and Deputy CM Devendra Fadnavis flagged off the trial runs on the city's first fully subterranean Mumbai Metro 3 line, here on Tuesday.

The work on the 33.50 kms long Metro 3 corridor started in 2016 and the first phase is likely to be completed by end-2023.

Shinde, Fadnavis and Mumbai Metro Rail Corporation Ltd (MMRCL) officials waved the green flag for the trial run at Sariputnagar in Aarey Colony temporary car-shed inside a 3 kms tunnel till the Marol Naka Station.

Speaking on the occasion, Shinde said that nothing will stop the progress of Mumbai and Maharashtra after the new government took office on June 30, 2022.

Fadnavis said that the opposition to the Metro car-shed in Aarey Colony was more political than environment-related and indirectly flayed the previous Maha Vikas Aghadi (MVA) Shiv Sena-Nationalist Congress Party-Congress government for delaying the much-needed project.

MMRCL officials informed that the test runs of the metro rakes over the next three-six months would comprise various parameters like speed, emergency brakes, oscillation in the tunnel - a first for Mumbai.

The Metro 3 line will connect Colaba in south Mumbai to SEEPZ in north-west, via Bandra with the first phase likely to be operational by Dec. 2023 and the next phase by June 2024, said the officials.

As per original plans, the line was slated for completion in December 2021, but was bogged down due to the car-shed row coming inside the Aarey Colony and the MVA government had shot down the proposal in November 2019, to shift the car-shed to a new site in Kanjurmarg.

After coming to power two months ago, the Shinde-Fadnavis government spiked the MVA's move and restored the car-shed location from Kanjurmarg back to Aarey Forest, attracting howls of protests from the Sena-NCP-Congress and environmentalists.

The delays have led to a cost escalation from the original estimates of Rs 23,000-crore to now around Rs 37,000-crore, and the complete project is now slated for completion only by mid-2025.

The current status of the project is nearly 99 per cent of the tunnel digging works are completed, 84 of the civil works, giving an overall project execution of around 70 per cent.

The 33.50 kms Metro 3 will have 27 stations en route, including 26 underground and one at ground-level, with a portion of the line running under the Mahim Creek and the Mithi River.