The first aerial shot of Mumbai Metro. The Versova-Andheri-Ghatkopar Metro service, which was earlier expected to kick off by April 24, will be delayed as the authorities are waiting for a nod from the Commissioner of Railway Safety.Last week, the joint effort by Mumbai Metropolitan Region Development Authority (MMRDA) and Reliance received a go-ahead from the Research Design and Standards Organisation (RDSO), Lucknow.The Congress - NCP combine wanted the metro to start functioning by April 24, the day Mumbai goes to the polls. Chief Minister Prithviraj Chavan, who is also the MMRDA chairperson, was especially keen on the date.Sources said Congress candidates Gurudas Kamat and Priya Dutt, and NCP candidate Sanjay Dina Patil want to derive maximum mileage out of the issue.Meanwhile, Commissioner of Railway Safety (Western) P S Baghel said, “I have just received the papers. I will first scrutinise them and then inspect the section. We might we call for clarifications. Our trials will start later. Normally, it takes three to four weeks.” He added that besides his inspection, the authorities will also need approval for the locomotives from the railway board.