MP Dr Andrew Murrison says he is disappointed by the response of the Trains Minister to his plea for better services on the Bristol-Waterloo line.

Trains minister Tom Harris has written to the West Wilts MP following their meeting last month regarding the service run by South West Trains that offers a direct service to the capital for towns in his constituency.

In his letter, the minister commits to the current level of service but seemed lukewarm on the prospects of the more frequent service that Mr Murrison is pressing for.

Mr Harris said in his letter: "Given the need to deliver the hourly Exeter service from December 2009 and the continued need to balance this with provision of sufficient capacity for Yeovil/Salisbury from London flows in the am and pm peaks, the ability to provide any extra commercial services from Waterloo to Bristol via Salisbury and Westbury may be quite limited."

Mr Murrison said: "It seems that any improvement in the service will be dependent on commercial viability and competing network priorities.

"Ministers and Network Rail must do more to increase capacity without which it seems unlikely that we will see much improvement on the direct service via Salisbury or the Trans-Wilts' route."