Scottish Premier League chief executive Neil Doncaster revealed consensus had been achieved at a meeting of the 12 clubs at Hampden today.
Scottish Football League clubs will meet to discuss the proposals, which include a merger of the two bodies, on Thursday.
Doncaster said: "We got unanimous backing of the way forward today so it now goes to Thursday and the Scottish Football League clubs will have their views.
"But today, the Scottish Premier League clubs were united in their view that this is the way forward."
The plans were originally backed by SPL clubs last year before Doncaster stepped up talks with his SFL counterparts.
But some doubt had emerged since both leagues agreed in principle to the plans earlier this month in conjunction with the Scottish Football Association, whose professional game board (PGB) has been driving reconstruction attempts.
Some clubs who were not involved in the previous meeting had requested more information amid scepticism from fans but they appear to have been satisfied today.
Doncaster said: "We provided further details that have arisen from meetings over the past weeks.
"The last time that all of our SPL clubs got together was on December 3 so in the intervening time there has been some more detail that's been discussed with the PGB and with the SFL board.
"All of that was provided today and the clubs are clear and united and unanimous in their view that this should be taken forward to the next stage."
The plans, if approved by the SFL clubs, would see both leagues merge and a fairer distribution of income, along with a pyramid system that would allow clubs to move into the professional league.
The controversial aspect of the new structure is a plan to split the top two leagues into three groups of eight after 22 games to create an extended play-off system.
The middle eight clubs would all have their points reset to zero and the top four at the end of the season would start the next campaign in the 'Premiership'.
The SFL needs 22 of its clubs to back the plans with Rangers not allowed to vote as they are only associate members.
Rangers came out vociferously against the proposals when the leagues reached broad agreement with chief executive Charles Green vowing to look for a way out of Scottish football if they were introduced.
Rangers would still be in the bottom tier if the new system comes into force in time for next season, but the timescale of their anticipated ascent to the top flight would not be affected.
However, there is no guarantee the plans would be ratified in time to take effect next season.
Motherwell will aim this week to meet directors of the Well Society, the fans' group which has a stake in the club, in order to state their case for change.
A club statement read: "There was no formal vote today however as a club, we indicated our support to the SPL executive to progress discussions with the SFL.
"It is now our intention to share what we heard today with our supporters so we can have the same discussion and outline why it is our view this is the best option for the game at this time."