Retaining the South Fylde railway line rather than converting it to a tramway is vital to boosting Blackpool's tourism, councillors have claimed.
Blackpool's Labour-run council has formally supported a move to seek investment for a passing loop on the line which would enable more trains to use the route which serves South Shore and the Pleasure Beach.
A notice of motion was passed at full council, although it was not backed by the Conservatives.
They are supporting a plan put forward last month by Blackpool North and Cleveleys Conservative MP Paul Maynard for an extended light rail tram loop around the Fylde coast, including links to Lytham and between Poulton and Fleetwood.
But Coun Martin Mitchell, who proposed the motion to retain the existing railway link to Lytham, said it would be better to invest in creating a passing loop on the South Fylde line.
This would enable more services to be run on the line as trains would be able to pass each other.
The motion was seconded by Coun David O'Hara, who said: "A passing loop would help us get more traffic in from East Lancashire and further afield.
"It would create extra capacity on the South Fylde line which will be a boost not only for Blackpool South but for Blackpool as a whole."
But Conservative Coun Paul Galley said light rail schemes had been more successful in attracting funding.
He said: "Do we upgrade it to light rail in the same way Manchester has done with suburban railway lines such as those going to Bury and Rochdale?
"Or do we continue hoping that one day we might get a passing loop?
"When I look at which services government support, light rail has been more successful."
The council passed the motion on a majority vote. The chief executive will now write to the Secretary of State for Transport and the chief executive of Transport for the North with a request for an upgrade of the South Fylde line and restoration of the rail linke from Poulton to Fleetwood.