Infrastructure Victoria is strongly opposing an extension of Melbourne's free tram zone, arguing it would overcrowd trams, direct investment away from other public transport and unduly benefit people who need it least.

The inquiry is considering an extension of the free tram zone. Credit:Joe Armao

Transport Matters MP Rod Barton has proposed extending the free tram zone to include the MCG, National Gallery of Victoria, Shrine of Remembrance, Melbourne Zoo and Royal Children's Hospital, in order to increase accessibility and boost tourism. He also proposes free travel for full-time students and senior citizens.

A parliamentary inquiry is examining the merits of his proposal.

Lord mayor Sally Capp is also in favour of the extension, but Infrastructure Victoria – the peak infrastructure advisory body to the state government – has warned against it in its submission to the parliamentary inquiry.