It's a long time since I did my ATC Legislation course, but there was something in The U.K.'s Air Navigation Order about 'Reporting of hazardous conditions'.
It was a short paragraph if I remember correctly, either in the 'Articles' or 'Rules Of The Air'. It wasn't specific to FOD and was wide-ranging in it's applicability, (I think). It may have been 'Pilot's report of hazardous conditions'. It was a long time-ago, but I would think it unlikely that it's not still there.
I spent some time yesterday trying to find it in the current 'on-line' version, but so far without success.