Practically, the use of this position started only 1984 during the 11th Knesset, with the first person to hold the position, Yitzhak Shamir, taking office on 13 September 1984. A Coalition deal between the Labour Alignment and Likud stipulated that Shimon Peres would be Prime Minister for the first two years of the Knesset term (out of four years), with Yitzhak Shamir serving as the designated Acting Prime Minister, and then swap places with Shamir for the next two. The major political parties, right-wing Likud party, then headed by Yitzhak Shamir, and Labour, then headed by Shimon Peres, did not gain enough seats in parliament, during the general election, to form a governing majority coalition, which enabled this coalition agreement to take place. The deal was continued into the 12th Knesset, but collapsed in 1990. The role of the designated Acting Prime Minister was limited and unattractive for any chairman of major party aspiring to get the top job.