NEW DELHI: Delhi Metro cards will be valid in 250 select city buses from Monday in a project that will eventually seek to merge Metro and bus travel, Delhi Transport Minister Kailash Gahlot said on Wednesday.The move is part of a month-long trial to shift to a 'Common Mobility Card' which could be used to travel in Metro, Delhi Transport Corp (DTC) buses and cluster buses in the capital.The 250 buses include 200 DTC buses and 50 cluster buses. Gahlot said the project would be rolled out in all city buses by April 1.During the trial, by tapping the Metro card on an Electronic Ticketing Machine or ETM in a bus, a ticket would be generated, which would also reveal the balance in the passenger's Metro card.Currently, ETMs are used by conductors in buses to issue tickets.The idea was first floated in 2010. The minister said it was delayed due to technical issues and lack of political will.The money deducted from commuters' Metro cards will go to Delhi Metro Rail Corp (DMRC), which currently issues the Metro cards. The money will be later transferred to the Delhi government, which has the RBI's permission.The minister said a MoU would be signed with DMRC on Thursday.Gahlot said that after the trial period, a new card would be designed which would have both DMRC and Delhi government etched on it.Commuters would be able to purchase and recharge these cards at all Metro stations, railway stations, airports, Inter State Bus Terminals (ISBTs) and DTC bus pass counters.The Minister said the government had been carrying out unofficial trial runs for the past two months to resolve different issues.