The SPFL tried to "unduly influence" the outcome of a members ballot on ending the lower-league season, says Hearts chair Ann Budge.
She says that the SPFL insisted the proposal had to be passed in order to release funds to clubs.
And Budge confirmed that Hearts will propose league reconstruction.
On Saturday, Rangers raised concerns over the process and the ballot hinges on Dundee, who have yet to vote despite a requested cut-off of 17:00 on Friday.
The SPFL has declined to comment on Hearts' claims after being contacted by BBC Scotland.
How we got to this stage
- To pass, the resolution on ending the lower leagues early due to the coronavirus pandemic needs to be backed by 10 of the 12 Premiership clubs, eight of 10 in the Championship and and 16 of 20 in Leagues One and Two.
- It has the necessary support from the Premiership and Leagues One and Two.
- Dundee are the only Championship club yet to vote. The count in this division is 7-2 in favour. Dundee intended to vote no, and the SPFL says the club submitted a voting slip, then retracted it.
- If passed, the SPFL's proposal would also lead to the Scottish Premiership season being declared if the league's board decide the remaining games cannot be played.
- That would see Hearts relegated from the top flight and Budge estimates it would cost the club "£2.5m-£3m in lost income next year".
Budge confirmed Hearts voted no to the proposal. They instead backed Rangers' counter plan by submitting an identical resolution, which Budge says was held up by the league.
She claims to have been told "from various reliable sources" that Championships clubs were advised at 16:30 on Thursday that the Rangers resolution had failed.
"I have to wonder why we were not so advised until lunchtime the following day," she said. "Once again, I strongly question the process."
Budge says the notes accompanying the SFPL's resolution included six options for how to decide the season, but was heavily weighted in favour of their own plan. She argues this was an attempt "to unduly influence the members' decision making process".
"Clearly, this is a subjective judgement," Budge said. "It suggests that the board has made a decision and simply wish now to convince the members to accept that decision.
"This is not, in my view, how you honour the principle that it is up to the members to decide how to ensure the fairest approach is taken."
On potential league reconstruction, Budge added: "Hearts, either alone or in conjunction with other clubs, will be proposing a temporary adjustment to the leagues, aimed at bringing matters to a close in a manner that ensures no club is financially penalised as a consequence of these exceptional circumstances."
Loans 'already within SPFL's power' say Rangers
In response to an SPFL statement, Rangers continued their criticism of the vote process after calling for an investigation and the suspension of SPFL chief executive Neil Doncaster and legal advisor Rod McKenzie.
They say their resolution was never about releasing end-of-season payments, but getting loans from the SPFL as advances for those monies.
And the club say they learned from McKenzie via email that if that was the case, their resolution was unnecessary because the league already have the power to loan money to members.
The spokesperson added: "The Inverness CEO, Scot Gardiner, confirmed on national radio yesterday that SPFL representatives made it clear on several conference calls that it was necessary to approve the SPFL resolution in order to release funds which would relieve the financial hardship being experienced by many clubs.
"Member clubs will be shocked to learn this is not the case and any club facing short term financial difficulties should request a loan from the SPFL immediately.
"Our resolution was never intended to release end-of-season fee payments but instead to provide loans as an advance on such payments. It is now apparent that this is already within the power of the SPFL.
"This provides further evidence that an independent investigation is urgently required."
SPFL chairman Murdoch MacLennan said: "I am entirely satisfied, based on all the information at my disposal, that the SPFL and its executives and legal advisers have acted wholly properly at every stage in this process."