1999 Uruguayan general election

Changes to the electoral law prior to the elections allowed third parties like the Broad Front a wider opportunity for participation. Parties were now required to hold primaries on the same day in April to elect a single presidential candidate; previously several candidates from a single party had been able to run for the presidency. The reforms also introduced the two-round system for the presidential election, with a candidate now required to receive over 50% of the vote to be elected in the first round, or face a run-off against the second-place candidate. Although the double simultaneous vote method (in which voters cast a single vote for the party of their choice for the Presidency, Senate and Chamber of Representatives) was retained, it prevented parties from submitting different lists.[6]

The 30 members of the Senate were elected by proportional representation in a single nationwide constituency,[7] whilst the 99 members of the Chamber of Representatives were elected by proportional representation in 19 multi-member constituencies based on the departments. Seats were allocated using the highest averages method.[8]

The requirement to choose a single presidential candidate created tension in some parties. The National Party chose Luis Alberto Lacalle, who had been president from 1990 to 1995. The Colorado Party primaries were won by Jorge Batlle, whilst the Broad Front selected Tabaré Vázquez.[9]

The Colorado Party spent the most on the campaign, spending the equivalent of US$11.1m ($3.1m in the primaries and $8m in the main election). The Broad Front spend $8m ($670,000 during the primaries and $7.4m during the main campaign) and the National Party $7m ($2m in the primaries and $5m during the main election). Other parties spent $500,000 during both stages of the elections.[10]