“A Call to Arms” began as an unfinished “bit” from the Genesis album sessions which none of the members liked, aside from Rutherford. Rutherford received permission from Genesis bandmates Phil Collins and Tony Banks to use it for the Mechanics, then developed it into a full song with help from Christopher Neil and B.A. Robertson.

Mike and the Mechanics — Wikipedia

Mike and the Mechanics (stylised as Mike + the Mechanics) are an English rock supergroup formed in Dover in 1985 as a side project of Mike Rutherford, the bassist/guitarist and one of the founding members of the band Genesis.