The Football Supporters' Association (FSA) now backs the 3Up campaign.
At the group's AGM, members backed the motion from Matthew Kempson of View from the Allotment End fanzine, which was seconded by Richard Tomkins from Hereford United Supporters' Trust.
It comes after an FSA survey found nine out of 10 fans backed the principle of increasing the promotion and relegation spaces between the EFL and the National League from two to three.
An overwhelming 92.5% of all fans said they supported the idea, with just over eight in ten (83%) of fans of EFL clubs backing the proposal.
More than 1,980 fans gave their opinions in a survey prompted by the National League’s 3UP campaign, which aims to increase the promotion and relegation spots between the fourth and fifth tiers of English football.
The most popular reasons fans gave for their support of the proposals was the idea that three up, three down was fairer than the current system (91.1%).
There was also strong support for the idea that it would enhance the sporting attractiveness of the football pyramid, with 90.4% agreeing with that sentiment.
Of those who were against the idea (just 6.4%) the main concerns were the idea that it would jeopardise the financial futures of more clubs/make it harder to run them sustainably (56.5%) and that there were bigger problems in the game that needed fixing (53.2%).
National League chief executive Mark Ives welcomed the FSA survey and noted the fans’ opinions with interest.
“We believe the 3UP campaign goal is vital to the overall health of the game,” Ives said. “It’s highly encouraging to see that fans of all divisions appear to feel the same – we have always believed that to be the case.
“We also think that 3UP ties directly into the government’s overall objectives for football and therefore should be as high on the game’s agenda as anything else this year – and not linked to wider regulatory matters that could potentially take years to conclude.
“We are lucky to have one of the best domestic football structures in the world but hopefully there is now the opportunity to make it even fairer by introducing 3UP.”