Thanks all they have now fixed the pipe but I am now chasing them for repairs to ceiling where water had started to come through and also an explanation of how this massive lapse in safety occurred - it's seems it's just by the grace if god there was no overflow and serious damage to the house or injury to any of us. The plumbing company that they had subcontracted the work to have since gone bust (unsurprisingly perhaps) so not really sure who I would report to who - but just thinking about what could have happened gives me the horrors