Vice Premier Shimon Peres ended months of speculation Wednesday when he formally announced his candidacy for president in a special Kadima faction meeting in the Knesset. Peres, 83, who lost the 2000 presidential race to Moshe Katsav, acknowledged that he was "not the youngest member of Knesset" anymore, but expressed his willingness to serve a cross section of Israelis in a seven-year term as president. "After a lot of contemplation, I decided to accept the requests for me to be a candidate for president of the state," Peres told the faction. "I decided to accept the position after I was approached by the prime minister, MKs and many Israelis from surprising places - simple folk as well as sophisticated people - who asked me to make this contribution, that I must say this might be my last contribution to the state." Knesset Speaker and Acting President Dalia Itzik, who would have run on Kadima's behalf if Peres did not, made a rare appearance before the faction and called Peres the best possible candidate. "I am pleased you assented to the prime minister's request and our requests to contend, even though you thought about it, in my view, for too long," she said. Itzik lashed out at Kadima MKs who intend to reject Peres for other candidates "out of a belief that they are God's messengers." Prime Minister Ehud Olmert reiterated his promise to "work tirelessly" to see Peres elected. In closed conversations he warned Kadima MKs that electing another candidate would weaken the party and supporting Likud candidate Reuven Rivlin would serve to strengthen opposition leader Binyamin Netanyahu. Rivlin distributed a letter to MKs warning that Peres would not bring honor or dignity to the presidency. In the letter he questioned whether Peres would have the energy to function every day at his age. "A blatantly political selection will transform the presidency into just another political position, and turning the presidency into a prize for lifetime achievement or political compensation for past disappointments will undermine the presidency's dignity," Rivlin wrote. Labor candidate Colette Avital said that while she respected Peres for his long history and service to the country, the time had come for a change in the political echelon. There has been speculation that up to a third of Kadima MKs plan to support Rivlin or Avital. Kadima MKs Marina Solodkin and Ze'ev Elkin have gone public with their decisions to support Avital and Rivlin, respectively. "There are many others in Kadima who are supporting Avital and Rivlin," Solodkin said. "The 'rebels' are well known." Elkin said he had received threats from Kadima activists in the Russian sector. He said he was considering filing a complaint against the party leadership for actively encouraging the pressure. Several Kadima mayors came to the Knesset on Wednesday to lobby for Peres.