Ok i know this is a long shot but im sure there was a song in the uk charts, done by two different artists, in the charts at the same time. I have no idea what year only that i think it must have been in the 1990's!
i'm sure there must be more but the one that comes immediatly to mind is the classic golden oldie Unchained Melody
No1 for Jimmy Young 6th May 1955
No 2 for Al Hibbler 13th May 1955
No 10 for Les Baxter 13th May 1955
and an instrunental version by Librace reached No 20 0m 17th June 1955. you cann't keep a good song down
And another is the Beatles number Michelle
No 1 for the Overlanders and No11 for David and Jonathon in the same week 13th Januay 1966.
I wished you hadn't started this post I've a feeling it's going to be one of those I cann't get out of my mind
This used to happen a lot in the 50s, 60s and early 70s. And I remeber once in the early 70s when there were two identical (it seemed to me) versions of the same song (Leader of the Pack) by the same group (Shangrilas) but on two different labels. Eventually the two sets of sales were combined for chart purposes but for a while both were in the top 10 at the same time
Thanks for all the suggestions guys but none of them is what i have in my head. Will keep thinking..... its doing my nut in. The only thing i remember is was a terrible pop song. Helpful i know