By the looks of things this leaking has been going on for sometime as the water has now soaked the plasterboard and the skirting, which in made of MDF.
So, time to get to work. I have removed the damaged plaster and skirting and pulled back the flooring to allow to dry. I have also removed the shower screen as this is where the water is getting through. The shower screen needs a new seal and lowering a bit as the gap between the screen on the bath is too big.
There, job done, just needs painting.