Within minutes of leaving the field at the end of Newcastle's 3-2 friendly defeat to Leeds United, Barton issued three Tweets that exposed his unhappiness at recent events at St James' Park.
He later posted a fourth comment claiming he did not want to leave the club, but citing a fear that the forthcoming season could turn into another battle against relegation.
The Magpies midfielder also expressed support for Jose Enrique, who was fined around £100,000 for similarly critical messages that were made via Twitter during the club's recent tour of the United States.
Enrique criticised the club's lack of ambition and reluctance to spend money during the current transfer window, and Barton voiced similar sentiments as he described Newcastle as a "once great club".
Barton tweeted: "If only we as players could tell the fans exactly how it is, without them above fining us lots of money. There will be a time and a place.
"If it wouldn't effect team morale and cause unrest within the dressing room, am certain Jose's comments would be the tip of the iceberg.
"And again it would be left to those magnificent fans to pick up the remnants of their once great football club.
"If I wanted to leave, I'd just come out and say 'I want to leave'. Things need addressing as am not prepared to go through a relegation again."
Barton ended his third message with the hash tag #hadenoughofcertainpeople, a comment that suggests his frustration has been building for a while.
Newcastle officials are aware of last night's developments, and a formal response is anticipated later today.