Literally!
The web contains a mine of information on travel to and from France - what is contained here can only be a summary. We concern ourselves principally with travel to our region, the Rhône-Alpes, but the information holds largely true wherever you are headed.
By Road/Ferry.
All the eastern and central channel ports are convenient for this part of France. Journey times will vary depending on your ultimate destination, but allow at least 6 - 7 hours driving time to Lyon
Le Havre - from Portsmouth by P&O Ferries
Caen - from Portsmouth by Brittany Ferries
Dieppe - from Newhaven by Hoverspeed
Boulogne/Calais/Dunkerque - from Dover by P&O Stena and SeaFrance ferries and Hoverspeed (SeaCat and Hovercraft.)
Visit the websites for sailing times and destinations.
By Rail.
Eurostar from London Waterloo ; change either at Lille Europe or Paris. Otherwise to Channel port by train and cross as foot passenger, and take French SNCF train on arrival. Lyon Part-Dieu station is about 6 hours from Waterloo.
Visit www.sncf.com for travel information
By air.
France is well served by both national airlines and by low-cost carriers. Easyjet fly from a number of UK airports to Geneva, and from London Stansted to Lyon. Ryanair fly from London Stansted to "Lyon" - actually to St Etienne, about 1 hour west of Lyon.
Visit the websites for full timetable and destination information. www.easyjet.com and www.ryanair.com. There are a couple of things to bear in mind for travelling with low-cost airlines:
By bus.
Coaches serve most of France from London; but we have never tried it so don't feel qualified to comment!