Transport for Wales has announced new premium intercity trains on its Holyhead to Cardiff line, calling at Shrewsbury Station.
It also plans to introduce similar trains on the Swansea to Manchester route, which runs through Shrewsbury and on to Whitchurch and Crewe.
Mr Paterson said: "It is positive that Transport for Wales is improving trains on routes through Shropshire, but there is still much to do.
"We need better scheduling and I would like to see Transport for Wales backing bids for Government funding for disabled access between platforms at Whitchurch Rail Station.
Last year Mr Paterson wrote to Chancellor Rishi Sunak asking him to direct funding towards Whitchurch station.
There is no disabled access for the station's south-bound platform, with anyone with mobility issues having to travel up to Crewe first if they can not use the footbridge.
Last year Whitchurch missed out on funding to improve stations, despite a long-running campaign from the town council.
"In many cases, people depend upon trains to access key services," Mr Paterson said.
"However, the southbound platform at Whitchurch can presently be reached only by footbridge, making it completely inaccessible for people in wheelchairs or with other mobility difficulties, as well as for those with pushchairs.
"Clearly, this is an unacceptable situation for which improvements are overdue."