The Hearts first team squad and PFA Scotland have submitted a formal complaint to the Scottish Premier League over unpaid wages at Tynecastle.
Action has been taken after payment of the players' salaries for December failed to arrive on time.
This is the third successive month in which such an event has occurred and, after instructing players' union PFA Scotland to act for them, the Hearts squad have taken their fight to the authorities.
It is anticipated the matter will be discussed at Monday's SPL board meeting, where all top-flight clubs will be represented.
The SPL confirmed receipt of the letter in a statement released on Friday.
It read: "The SPL received a letter from PFA Scotland this afternoon on behalf of several PFA members.
"This letter will be considered by the SPL board at its meeting on Monday. No further comment will be issued at this time."
Meanwhile, Andrew Driver appears to have played his last game for cash-strapped Hearts.
Having been excluded from the club's first team plans of late, he is now looking to move on.
Scott Fisher, who represents the player, has confirmed that Driver is unhappy with his current situation and plans to hand in a written transfer request on Monday.
He said: "The player has spoken to Paulo Sergio and told him of his desire to leave because of a lack of opportunities."