OK, what with one thing and another it is now a lot cheaper for me to dump the OH in Spain (lucky cow) rent a room and work in the UK while commuting to and fro, one week on two off and vice versa.

Obviously I need to stay in the UK for more than half the year to have all my tax affairs in the UK, but is that the best way to go?

What are the pros and cons of Spain vs the UK for tax and commuter work like this?