It is currently the main opposition party, having lost the 2020 Belizean general election, after previously holding the government across three prior terms.

In 1973 political opposition in Belize was weak and the ruling People's United Party (PUP) had never lost a legislative election since its foundation.

Controversially, a significant portion of the United Black Association for Development also voted to join the UDP upon foundation.

Former People's Development Movement head Dean Lindo was subsequently named party leader.

[9] However, they were soundly defeated in the 1998 elections as the PUP won 26 of the 29 seats, after which Esquivel was replaced by Barrow as party leader.