The three main players are the Department for Transport, First Great Western (although Stagecoach / South West Trains could also fit that role), and Wiltshire County Council.   Network Rail have a major role too - just slighly less than the other three.

With a great deal of discussion going on at the moment, the four people listed here are the senior people who are probably best placed to help our case along without being so senior that they are completely detached from the decisions and saying "why bother me".   In other words - I think they're good people to provide with lobby information.

Miss Fleur de Rhe-Philipe
Cabinet Member for Environment, Transport and Economic Development
Wiltshire County Council
Paddock Gate
Upton Scudamore
Warminster
Wiltshire
BA12 0AQ

Miss Fleur de Rhe-Philipe - Cabinet Member for Environment, Transport and Economic Development

Performance and strategy for transport (including the Local Transport Plan, related strategies and policies, highways, maintenance; improvements; traffic management, rights of way; road safety); passenger transport; trading standards; emergency planning and economic development.

Dave Ward
Route Director (West)
Network Rail
125 House,
1 Gloucester St
Swindon, SN1 1GW

I have no "job specification" as such for Dave's role, save that he is in charge of all the Network Rail territory West from Paddington and that includes the TransWilts to just south of Warminster. See http://www.firstgreatwestern.info/info/703_Network_Rail_Introducing_Dave_Ward.html

Peter West
Great Western Franchise Manager
Rail Division
Department for Transport
Great Minster House
76 Marsham Street
London
SW1P 4DR

Peter West is the Civil Servant who looks after the ongoing First Great Western Franchise, which includes continuing consideration of TransWilts services.

John Curley
Route Director West
First Great Western
Milford House
1 Milford Street
Swindon
SN1 1HL

John Curley is the First Great Western route director charge with - over a very few months - putting the things that have gone wrong in these parts right. See http://www.savethetrain.org.uk/forum/index.php?topic=4474.