Jack said that he would kill anyone who gives ralph food. And they would cook the body and eat it.
During the confrontation on the causeway leading to Castle Rock Ralph first called Jack a "Thief" and later when his temper was pushed beyond breaking point he screamed at Jack, "You're a beast, and a swine and a bloody, bloody thief!""
Ralph doesn't tell Jack about the glasses as Jack already knows about them, mainly because he stole them. Ralph pointed out that Jack could have had fire at any time if he'd simply asked for it but instead he'd come sneaking up like a thief and stole Piggy's glasses. Jack demanded that he repeat the accusation and when Ralph obliged Jack rushed forward and stabbed his spear at Ralph's chest. Ralph managed to block the thrust with his own spear and then swung it around to land a stinging blow to Jack's ear.
No
Jack merridew! Jack merridew!
After Ralph won the election to be chief, leaving jack as the losing candidate, Ralph placed Jack in charge of the choir and allowed Jack to choose what he wished them to be. Jack chose, "Hunters."
By having all the boys against Ralph making him the outcast now. And since jack knows the boys are scared and want to feel protected and belonged and ralph doesn't provide any protection against the beast. Jack also makes Ralph look really bad like a beast making the boys go against Ralph.
Jack's boys do not attack Ralph's boys at any point in the book. Roger and Maurice accompany Jack on a night time raid on the shelters but the purpose is not 'attack' anyone but simply to steal Piggy's glasses. Even when Ralph, Samneric & Piggy go to castle rock to demand the return of Piggy's glass although they are vastly outnumbered by Jack's tribe they are not attacked.
Ralph suggested that they needed to build a fire to attract any passing planes or ships if they wanted to be rescued. Jack led the boys up to to the top of the mountain to build the fire. Both Ralph and Jack worked hard to build a huge bonfire and then, they realised that they had nothing to light it with. They had no matches, no cigarette lighter, nothing. That is why they were both embarrassed.
Ralph and Piggy develop personal-friend bonds, Ralph playfully teases Ralph while the other boys condescend him, Ralph is the only boy who defends Piggy however. Piggy stresses that Jack is against civility, which Ralph stands for, Piggy says that Jack holds no regard for Piggy, nor any concern for him.
Jack made that statement when his call for a vote of no confidence in Ralph's leadership was ignored by the rest of the boys.
Ralph feels that it is his duty as chief to go and look for the beast. Uppermost in Ralph's mind is the need to relight the fire so that they can be rescued, he views the beast as an obstacle which is preventing this. Jack is the self appointed head of the hunters and as the task involves hunting and tracking he is an obvious choice to go too. Jack also wishes to be leader, so he can't allow Ralph to gain prestige from doing something alone, Jack wants his full share of any glory.Ralph feels that it is his duty as chief to go and look for the beast. Uppermost in Ralph's mind is the need to relight the fire so that they can be rescued, he views the beast as an obstacle which is preventing this. Jack is the self appointed head of the hunters and as the task involves hunting and tracking he is an obvious choice to go too. Jack also wishes to be leader, so he can't allow Ralph to gain prestige from doing something alone, Jack wants his full share of any glory.
After Ralph, Jack and Riger returned from seeing the "beast" on top of the mountain Jack called a meeting and accused Ralph of calling his hunters cowards which was a lie. He then held the conch against his chest and asked, "Who thinks Ralph oughtn't to be chief?" The assembled boys remained silent and Jack asked again, "Hand's up... Whoever wants Ralph not to be chief?" the silence continued until Jack eventually put the conch carefully down and left, saying "I'm not going to play any longer. Not with you. I'm not going to be part of Ralph's lot___" So the simple answer to your question is that Jack called for a vote of no confidence in Ralph and lost.