It's a blooming long way but unfortunately the ferry from Portsmouth to Bilbao or Plymouth to Santander is about £400 each way! I'm doing the latter next month but that's because I'll be in a 30 year old MG and wouldn't fancy Calais to Vera.
You can sail from Portsmouth to St Malo which is cheaper (takes 10 hours) and the drive to Vera is then about 1100 miles.
Cheers.