Need some advice (blood issue)

Hi all. Had a conversation with my wife about the blood issue this week. She made it very clear that if there was a situation where our two young children needed blood and I wasn't there, she would refuse it. I know that her family (who regularly look after our children), would take the same stance.

I need to know where I stand on this, and what to do in order to protect my children. While I disagree with most of the orgs rules and teachings, I can live with the relatively benign ones for now. However this is different, this is the direct safety and potential health of my children. I'm based in the UK, has anyone else been in a similar situation, and if so do you know the protocol here? Do I need to lawyer up at this point?

Thanks in advance.