Prime Minister Binyamin Netanyahu, who was one of the most vocal critics of former prime minister Ariel Sharon, has ironically proven to be his political heir, Sharon's longtime spokesman Ra'anan Gissin said Sunday, on the eve of the fourth anniversary of the stroke that ended Sharon's political career. Gissin, who worked for Sharon for a decade, noted that Netanyahu, like Sharon, moved to the center of the political map after becoming prime minister, formed a national-unity government, and is expected to approve a prisoner exchange with the Palestinians. He said Netanyahu followed the "Sharon school of thought" when he unilaterally froze West Bank construction and negotiated territorial compromise with the Americans before doing so with the Palestinians. "Those who claimed to be Sharon's successor failed because the tsunami waves that came after his disappearance were too much for them," Gissin said. "The tragedy is that his fiercest critics such as Netanyahu turned out to be his real successors. Netanyahu hasn't formed a Kadima, but he has realigned his own party in the Center to allow himself to make the decisions he has to make regarding the fate of the Palestinians." Sharon has been in a coma since his second stroke on January 4, 2006, and is still connected to life support systems at the Chaim Sheba Medical Center in Tel Hashomer. Gissin said that were he to wake now, he would be disappointed by the outcome of at least two of his ventures: The Gaza Strip withdrawal and Kadima. "If he looked at Kadima, he would say this baby was taken out of the incubator way too early," Gissin said. "It's not what he wanted. The ripple effect of his premature departure is still felt four years later." Other Sharon advisers said Netanyahu still had to prove himself before they would mention him in the same breath with their former boss. If he followed through with pullbacks in the West Bank, they would respect Netanyahu, but he would then have to apologize to Sharon for criticizing him so fiercely. "Netanyahu is now facing the same poison from extremist elements in his party that Sharon did from him, but without the leadership and courage that Sharon had," former Sharon strategist Lior Chorev said. "The question is whether Netanyahu has the courage to understand that leadership has a price and will 'walk the walk' and not just 'talk the talk.' Bibi hasn't proven yet that he will do what he says. We are waiting to see if he will be a leader or a slave of his Likud." Sharon's legislative adviser Oren Magnezy said it was unfair to compare Sharon to any current leader, because he was larger than life. He said Netanyahu was imitating some of Sharon's tactics, but he remained unconvinced that he had actually changed his opinions the way Sharon did in his shift away from the Right. "We will only see if he has really changed if he takes on the settlers and his political base," Magnezy said. "When I believe he has made the leap into compromise, he will have to apologize to Sharon, but I don't think he has made that leap yet." Sharon's political adviser Erez Halfon, who is currently vice chairman of the Nefesh B'Nefesh aliya organization, said Sharon personally had a difficult time with the Gaza Strip disengagement, but he thought it would bring Israel security, and a diplomatic horizon and show the world who is for peace and who is not. He said he did not know how Sharon would feel if he saw the result of it and that it was still too early to judge the move. "Sharon will be remembered as a real bulldozer who could move things in every office he held," Halfon said. "I still hope a miracle happens and he is allowed to end his life in the country he loved so much in a very different way than the tragic situation he is in right now." Sources close to Netanyahu responded to the criticism by saying that the prime minister hoped Sharon would make a full recovery but that he did not intend to model his premiership after his. "Netanyahu is not following the path of Sharon and he still criticizes the disengagement all the time," a source close to Netanyahu said. "The prime minister wishes Sharon a full recovery so they can argue again in the future."