The United Development Party (Indonesian: Partai Persatuan Pembangunan, PPP or P3), is a one of the Islamist political party in Indonesia. At the time of its declaration on January 5, 1973, this party was the result of a merger of four religious parties, namely the Nahdlatul Ulama Party (NU), the Islamic Education Movement (PERTI), the Indonesian Islamic Union Party (PSII), and the Indonesian Muslims' Party (PARMUSI). The first chairman at that time was Mohammad Syafaat Mintaredja. The merger of the four religious parties was aimed at simplifying the party system in Indonesia in facing the first general election during the New Order in 1973. Because the party's distinctive logo was associated with Islamic religious politics, the PPP was popularly known as the Ka'bah Party.

Ten political parties participated in the 1971 legislative election, a number that President Suharto considered to be too many. Suharto wished that political parties be reduced to just two or three and that the parties should be grouped based on their programs.

The basis for the merger that would result in the birth of the PPP was a coalition of the four Islamic Parties in the People's Representative Council (DPR) called the United Development Faction. This faction consisted of Nahdatul Ulama (NU), the Indonesian Muslims' Party (PARMUSI), the Indonesian Islamic Union Party (PSII) and the Islamic Education Movement (PERTI).

The United Development Party (PPP) was founded by

The leaders of four Islamic parties participating in the 1971 election and the head of the United Development Group, a faction of the four Islamic parties in the House of Representatives (Indonesia) (DPR).

With encouragement by the Government, officials from all four parties had meetings with each other and after finding some common ground, merged the four Islamic parties in Indonesia into the United Development Party on 5 January 1973. Despite this formal merging of the parties however, internal PPP politics under the Suharto government were dominated by the differing priorities of the original groups that formed the party.

In the mid-1970s, popular support for Suharto's regime was rapidly waning. When Suharto had seized power with a bloody military coup in 1965 and ousted President Sukarno, the Islamic groups had supported Suharto and aided in persecuting his political opponents. But as the regime had become corrupt and even more authoritarian, this alliance began to crumble. As the 1977 legislative election approached, many began to seek other options to vote for aside from the government-backed Golkar.

Worried that the PPP might win the elections, Suharto played on the fears of the people by having the military arrest a group of people who claimed to be associated with the Jihad Commando (Komando Jihad). With this some people became worried that to vote for the PPP and its Islamic leaning would mean expressing support the Jihad Commando and in a government growing increasingly authoritarian, many simply refused to be associated with the wrong side. Golkar would go on to win the legislative elections with 62% with the PPP coming second with 27% of the votes.