Beziers is our nearest mainline station though if connections suit, and you're hiring a car, any of Montpellier, Carcasonne and Narbonne provide viable alternatives to Toulouse.
Eurostar (0870 160 6600 www.eurostar.com) have service from to Avignon, Narbonne and Beziers.
You can also go Eurostar to Lille and then hop on the TGV or change to Rail Europe (08705 848 848 www.raileurope.co.uk) giving 12 days unlimited travel in France for £169.
Services with sleeper accommodation run from May to September from Calais to Avignon/Nice/Brive/Toulouse and Narbonne. Local trains sometimes have special summer offers to go almost anywhere local for just 1 euro