Promoted clubs Dundee United, Raith Rovers and Cove Rangers have said they will “robustly defend” their petition after Hearts and Partick Thistle lodged legal action to reverse the outcome of the season.
The demoted clubs went to the Court of Session after describing their relegation – and that of Stranraer – as “unfair and unjust”.
The petition demands financial compensation only if the clubs fail in their bid to be re-entered in the Premiership and Championship respectively.
The promoted clubs have since released a joint statement confirming they had been served a petition by the two clubs.
They said they were “extremely unhappy” to have been “drawn into this legal action”, adding they “immediately instructed external lawyers to act on our behalf and to protect our clubs’ interests.”
The statement continued: “The legal action that has been raised by Heart of Midlothian and Partick Thistle not only threatens the financial stability of the SPFL, but also its individual member clubs.
“For all of these reasons, we must and will robustly defend our position.”
Hearts, Thistle and Stranraer had their relegations confirmed on Monday after reconstruction proposals were voted down.