The 33-year-old's international career appears to be over following the decision, and the former Three Lions star was hugely critical of the move in his column in The Mirror.
"Imagine England dropping Wayne Rooney and telling him he will never play for his country again without saying why," he wrote.
"Well, I've got news for the amateur comedians who run the ECB. We want answers, the truth. We want detailed, precise reasons behind their decision to end Pietersen's international career.
"If you sacked a factory worker on the shop floor without telling him why he's been fired, he would take his employers to the cleaners through the courts. The ECB's handling of KP's dismissal has been pathetic."