The independent move by United players came as talks continued between the PFA players' union and the Football League and Football Association, looking at possible wage cuts or deferrals during the current shutdown of the game.
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Professional football in England has been suspended until April 30, at the earliest, due to the pandemic with some top-flight clubs putting non-playing staff on leave.
Health minister Matt Hancock said on Thursday that players should take a pay cut and "play their part" after he was asked about the morality of clubs using the government's job protection funds for non-playing staff while still spending huge salaries on players who are sat at home on full pay.
Prominent opposition Labour MP David Lammy had earlier said: "It's criminal that Premier League footballers haven’t moved more quickly to take pay cuts and deferrals."
The comments from politicians led a number of former players to rush to the defence of their profession.
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Former Manchester United captain Gary Neville, now a television pundit and businessman, defended the players and turned on the health minister.
"The PL players are more than likely working on a proposal to help clubs, communities and The NHS. It takes longer than 2 weeks to put together. Matt Hancock calling them out when he can't get tests in place for NHS staff is a f*****g cheek!," he wrote on Twitter.
Ex-Manchester City and Newcastle United midfielder Joey Barton, now manager of League One Fleetwood Town, said Hancock was diverting attention on to football.
"NHS under funded and mismanaged for decades? That’ll be the Premier League footballers fault. Wake up! This is about shifting the focus away from the government handling this pandemic horrendously," he wrote on Twitter.