Labor party leader Amram Mitzna told close associates last night that the chances of entering into a national unity coalition government headed by Prime Minister Ariel Sharon are slim to none. Mitzna will be meeting for the third time this Friday with Mr. Sharon, but most party leaders feel that chances for a unity government at this time are not great. MK Shalom Simchon said today that the situation could be different towards the end of the year. Shimon Peres is reported to have said that Mitzna's pre-election announcement that he would not join a unity government with Sharon cost Labor four Knesset seats in the election.