Dundee United chairman Stephen Thompson has accused the Old Firm of "undermining'' the Scottish Premier League after the chief executives of both Celtic and Rangers reiterated their desire to leave.
Celtic's Peter Lawwell outlined his wish for an invitation to a more lucrative league while Martin Bain of Rangers claimed his club would probably leave Scottish football within 10 years.
Thompson claims those statements jeopardise the SPL's commercial interests as the league bids to steer clubs through turbulent economic times exacerbated by the demise of former broadcasting partner Setanta.
"It's very unsettling for the SPL,'' Thompson told BBC Scotland. "We're trying to strengthen deals with commercial customers, TV deals, etc. If you're talking about the Old Firm leaving, where does it leave us with regards to contracts?
"We have got a five-year deal with ESPN and Sky with a three-year break. I assume if they went somewhere else, that contract would be null and void. It would have serious consequences on the game.''
SPL chief executive Neil Doncaster also branded Lawwell's comments "unhelpful'' as he focuses on bringing more income to the 12 clubs.
"I don't think the Old Firm, particularly Celtic, really care about anyone else,'' added Thompson, who challenged Lawwell to explain his intentions at the next SPL meeting. "After the demise of Setanta they had a go at all the clubs for voting for the current deal. Now they are undermining the SPL again.
"I don't know what's trying to be achieved. Potential sponsors don't know where they're going to stand in two or three years.''
Much of the recent speculation surrounding the Old Firm's future has centred on plans for a English Premier League 2 that may be discussed at the next Premier League meeting.
But Bain sees a European league as a more likely scenario than an invite to the English ranks.
"There are a number of like-minded clubs like Rangers and Celtic throughout Europe - big, big clubs playing in smaller leagues - who are hamstrung by their environment,'' he said.
"I think, as that groundswell grows, UEFA will take note of it and that will maybe lead to other things.''
But he added: "If the Premier League or a lower league want us and the arithmetics are right, and it's right for the club as a brand, then it's something we will explore.''
Lawwell had earlier admitted he was in "awe'' of the Premier League's "fantastic product'', while admitting an extension of the Champions League would be a "natural'' solution for Celtic to expand their income base.
But he also refused to rule out a move to the bottom level of the English leagues.
"We're in a watching brief,'' Lawwell said. "Fundamentally, we need someone to want us. We'll be waiting for someone to want this magnificent football club to come and compete with them, and if that benefits Celtic and its supporters, then we would be delighted to take part.''