SEOUL, South Korea (AP) — Candidates for South Korea's presidential election began their formal campaigns Tuesday in a race tainted by intense political strife over allegations involving the main candidates and their families.

Liberal governing party candidate Lee Jae-myung and his conservative opposition rival Yoon Suk Yeol are the major candidates of the 14 registered with South Korea’s election authorities. Recent opinion surveys show them running neck-and-neck.

The March 9 vote comes as South Korea faces a range of critical issues such as an economy hit by the COVID-19 pandemic, an advanced North Korean nuclear program and an intensifying rivalry between the U.S. and China. Both Lee and Yoon have been criticized as lacking clear, long-term foreign policy and strategies to handle other challenges while instead focusing on negative campaigns to attack each other.

Lee has faced an allegation that he was involved in a dubious property development project launched when he was a city mayor. His wife recently apologized over allegations that she had civil servants do her personal errands. Yoon, for his part, has faced an allegation that he resorted to shamanism, while his wife apologized for allegedly exaggerating and falsifying her professional careers.

The winner of the election is to be inaugurated as South Korea’s next president on May 10 for a single five-year term. Current President Moon Jae-in is barred by law from seeking reelection.

During the 22-day official campaign period, the candidates and their election campaigners can deliver speeches at public places, run campaign ads on newspapers, TV and internet and send text messages and emails to voters, according to the National Election Commission.