Zambian opposition leader Hakainde Hichilema on Wednesday accused ruling party officials of plotting to assassinate him ahead of general elections next year.
Hichilema, 58, leads the southern African country's main opposition United Party for National Development.
Known as "HH", Hichilema grew concerned for his safety this week after local media reports that he had a hand in the privatisation of state companies in which he then bought shares.
Government officials on Tuesday accused him of "corrupt practices" and vowed to investigate the matter.
Hichilema has denied any wrongdoing and said ruling party officials would use the allegations as an excuse to "eliminate" competition.
"They are dead scared of our growing popularity and they don't want HH nearer and so they are planning to kill me," Hichilema told AFP by telephone on Wednesday.
"These people are scared of me and they plan to kill me once they fake my arrest, but I am not scared to die," he added. "I am prepared to pay a sacrifice in defence of public interest."
Government spokeswoman Dora Siliya was not immediately available for comment on Hichilema's concerns.
Zambia's President Edgar Lungu -- who took office after the sudden death of his predecessor in 2014 -- has been accused of cracking down on dissent to consolidate power ahead of the August 2021 vote.
Hichilema lost to Lungu in 2016 elections and rejected the result.
He was jailed for four months the following year for allegedly refusing to give way to a presidential motorcade.
Tensions flared again in 2018, when Lungu successfully asked the constitutional court to allow him to run again.
The opposition claim this breaches the two-term constitutional limit, as Lungu will in effect have served three times if re-elected in 2021.
Zambia has enjoyed relative stability since its first multi-party election in 1991, which ousted the country's long-running post-independence leader Kenneth Kaunda.