Conservative MP Douglas Ross is set to miss the Universal Credit vote because he will be running the lines at a Champions League football tie in Barcelona.
Mr Ross has been listed as assistant referee at the Camp Nou stadium for Wednesday night's match against Greek side Olympiacos.
The game kicks off at 7.45pm UK time - 45 minutes after MPs at Westminster are expected to vote on the Labour motion.
Up to 25 Conservative MPs are thought to be willing to rebel and back Labour in the non-binding vote.
Mr Ross ousted the SNP's Westminster leader Angus Robertson to win the Moray seat in June's General Election and the Tories insisted his constituents supported his refereeing work.
A spokesman for the Scottish Conservatives said: "There will be many Scottish Conservative representatives in this debate.
"Douglas has held more than 50 surgeries since becoming an MP and has met personally with (Work and Pensions Secretary) David Gauke to discuss local cases which have arisen from those."
Shadow Scotland Office minister Paul Sweeney said: "It shows a perverse sense of priorities that Douglas Ross is off working a second job in Barcelona while Parliament debates the huge damage that universal credit is causing in our society tomorrow.
"This sorry episode will leave Mr Ross's constituents in no doubt as to where his priorities lie and it's not playing the game for them."