Lol, In April 1993, he delivered his famous speech to the nation on PTV in which he said that he would never take any dictation, referring to Army’s pressure to force him to resign. Army was with Ghulam Ishaq Khan. He then bid farewell to IJI ( a remanent of establishment) and formed his party, PMLN, which took part in 1993 elections and came second.
His second wave of opposition to establishment came in July 1999 when he knew that Mush kept him in darkness. He wanted to punish Mush in October 1999 for that act of foolishness , which was an act of bravery and the big proof of being anti-establishment. Remember, Zardari didn’t even show intention to punish establishment in 2011 over OBL fiasco. Similarly, in 2009, Nawaz wanted PPP to initiate Article 6 against Mush but Gilani said that it was not doable.
From 2004 to 2007, he gave various interviews ( reference: Sohail Warraich, Rauf Klasra) abroad where he vehemently opposed role of military in politics. From 2008 to 2011, he gave various statements where he said that he wanted to improve relations with India but Army impeded his way. I still remember his famous speech of May 28, 2010. Just watch that historic speech on Youtube.
BTW, what’s your definition of being anti-establishment? LOL...