Rescuers say they have broken through to 41 workers, trapped in a tunnel in Uttarakhand state since 12 November.
The men became stuck after a landslide nearby brought down a mountain of debris - none are thought injured.
They will now be extracted one by one via a 90cm diameter pipe inserted through the rubble of the collapsed tunnel.
Having to cut through metal rods has repeatedly impeded the rescue, and loose soil and hard rock have slowed progress.
Last Friday, officials said the workers would be out in a matter of hours - until a giant drill broke down inside the tunnel.
Authorities have been supplying the men with oxygen, food and water through a separate narrow pipe
