there was a song in butterflies

hi, i know this is a long shot but has anyone seen or got the series butterflies? in series 4 there is a song playing on the radio in both their cars as they are driving and its you've lost that lovin feeling. it is a really nice version but i cant find out who sung it. it isnt the obvious ones i have checked.

Hi there
This song has been covered several times by artists such as:

Westlife on The Love Album
Elvis Presley
Cilla Black
Neil Diamond and Dolly Parton
Lee Hazelwood and Nancy Sinatra
Dionne Warwick (USA #16, 1969)
The Human League, on their 1979 debut Reproduction
Long John Baldry and Kathi MacDonald (USA #89, 1979)
Roberta Flack and Donny Hathaway (USA #71, 1971)
Daryl Hall and John Oates (USA #12, 1980)
Erasure
The Flying Pickets on Lost Boys (album)

Hope this of some help to you

all i know is the man has quite a deep voice and as this series of butterflies was in the 80s and it was playing on the radio it must be before then