Mark Halper has filed suit in a U.S. court demanding recognition for inspiring the tune, claiming lyrics from his 1986 demo Don't Throw Our Love Away were clearly lifted for Smith's 2014 release.

In legal papers obtained by TMZ.com, he explains his track begins with the "phraseology and significant phrase, 'stay with me'", which he believes was ripped off by Smith, as the Brit uses the same three words repeatedly on his Grammy Award-winning ballad.

Smith is not named as a defendant in the suit - instead, Halper is going after bosses at a number of record labels, seeking a recommendation to executives at the National Academy of Recording Arts and Sciences for him to be handed a Grammy Award for his alleged contribution to Stay With Me.

It's the second allegation of copyright infringement Smith has faced over the track - in January (15), the star agreed to give Tom Petty and Jeff Lynne co-writing credits on the hit due to similarities between his song and the rockers' 1989 hit I Won't Back Down.