A 'bottleneck' station on the Merseyrail network could threaten its ability to cope with an expected increase in passenger numbers over the next few years.
Usage of the network has been going up - and bosses are expecting numbers to rise even further after the introduction of new trains next year.
But there is concern that Liverpool Central, a key interchange on the network, is already at full capacity and will struggle to cope with any more passengers.
It is one of the busiest train stations in the country outside London.
The combined authority's transport plan, which was approved in draft form by the transport committee earlier this month, says increasing capacity at the station is 'vital' for the region.
The report says: "At present, the station is at full capacity and acts as a 'bottleneck' for existing services, and a constraint in the very near future on any ambition to deliver improved rail connectivity to underserved parts of the City Region and to accommodate projected and desired growth in passenger numbers."
The plan calls on the authority to look for evidence, funding and options for ways to solve the station's capacity problem - and that could include major construction work on the station.
"This solution could entail a major remodelling of the station and associated platforms."
Liverpool Central has already gone through a number of changes in recent years.
The shopping centre on top of it is currently going through its own renovation after being bought by the council .
And the station itself was closed for a number of months in 2012 for renovation work on the platforms.
