Greg Mulholland (Lib Dem, Leeds North West) said both proposals could form part of the solution to local transport problems.
The West Yorkshire Integrated Transport Authority’s Scrutiny Study is not yet complete, but campaigners fear the Horsforth Woodside and Arthington station bids have already been discounted by the Passenger Transport Executive, Metro.
Mr Mulholland said opening both stations would allow more commuters and shoppers to travel without using their cars.
And he said after that happens, and the line is electrified, there could be a mixture of express, limited-stop trains and others that stop at all the stations.
He said: "I have written to Metro to urge them to reconsider opening Arthington and Horsforth Woodside stations and have since learnt that the bids are still under review.
"Both former stations could provide enhanced transport links to local residents and with the current proposed housing developments it is apparent that the present infrastructure will soon be insufficient.”