I don't know if you have already purchased your Eurostar ticket. However, if you are London based, an alternative is to go with Easyjet from Gatwick to Biaritz. This might work out cheaper than the train. The flight gets you in for mid day. You can catch a bus from Biarritz airport to Bayonne train station. This is what we did last August and managed to get to St. Jean de Pied de Port in time to get our credencial at the Pilgrim's office. You should probably book a place ahead of time in St Jean. The train ride is where we first got our 'camino buzz'. Over half of the people on board had large rucksacks, so we knew they were peregrinos. Once you get out of the train at St Jean, just follow the backpacks. They will lead you to the pilgrims office. I would also recommend buying a shell at St Jean. We had heard about shells on the camino and had read somewhere that you traditionally left something at the iron cross. So, we got the smallest shells that we could find locally and drilled holes in them. We even had a spare shell. When I got to St Jean, I saw the large scallop shells and had shell envy. I wanted to buy one and my boyfriend wouldn't let me (we already have enough junk to carry, you don't need a shell). So, we went up and over the Pyrennes without a large scallop shell. When I was in Roncesvalles, I went ahead and bought two shells anyway. He rather reluctantly attached his to his bag. Needless to say, by day three, he became very attached to his shell and would constantly check to see if it was still attached. Our small shells were left at the iron cross. Our large shells made it all the way to Santiago and live on a shelf in my living room awaiting their next camino. You can fly back from Santiago to Stanstead with Ryan Air.
