Gary Neville says the rivalry between Manchester United and Liverpool fans should be put on hold in order to fight the Super League.
Both United and Liverpool have signed up to the plans, which have triggered civil war to break out in football.
Sunday evening's announcement saw the somewhat bizarre spectacle of United co-owner Joel Glazer having a statement published on Liverpool's website in a move that was labelled an example of how out of touch the proposals are with fans.
Neville's impassioned anger at the Super League proposals has gained a lot of attention, with the former United defender calling on players and fans to mobilise against the breakaway competition.
For Neville, that means calling a truce on any on-the-pitch rivalry in order to fight what is happening off the pitch.
Speaking with Jamie Carragher on Sky Sports' Monday Night Football, Neville argued that fans' feelings toward the Super League are so strong that the duo could visit Anfield and Old Trafford respectively in protest at the plans and be welcomed.
He said: "On this issue, there’s the biggest rivalry. Honestly, he [Carragher] could go and stand on the Stretford End in a protest before the match and he’d be left alone and supported.
Manchester United are in the semi-finals of the Europa League after Edinson Cavani's volley helped the Reds complete a 4-0 aggregate win over Granada and set up a last four clash against Roma.
It's back to Premier League action this weekend when Burnley visit Old Trafford on Sunday.
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"I’m not sure I could go and stand on the Kop, but I genuinely believe on this issue, I could go and stand on the Kop and it would be together.
"On this particular issue, there is a truce, forget it, this is more important. I said before: forget your allegiances.
"The reason we’re critical of these two clubs is because we expect more of them, we expect more of them."