Hello

We are looking to travel to the UK from Northern Spain this christmas.  We are thinking of using the night train from Dax to Paris as it’s very tight to make the whole journey in one day.  From doing a bit of research it looks like the night trains go on weekday nights but not weekends.  But the day we want to travel is Friday 21st December and there does not appear to be any information for that train yet.  

I need to book the seats for the Eurostar and worry they might run out (we are a family of 4), but want to link them with the night train.

Is there a phone number I can call (in English) to find out if the night train will run of that day?  

Thanks,

Martha