The Zambian government is said to have deregistered an opposition party led by ex-Foreign Affairs minister Harry Kalaba who resigned in January citing corruption.
“It has come to my attention that the Democratic Party has been deregistered on account of having invited me to stand as their presidential candidate in 2021,” Mr Kalaba is quoted as saying by a private daily newspaper, The Mast.
A few days before he quit, Mr Kalaba, denounced corruption and poor governance, ruffling some members of the ruling party who called for him to resign.
Mr Kalaba was first appointed to Cabinet in 2014 by the late president Michael Sata and continued in his position under President Edgar Lungu.
He was the third minister to leave office after President Lungu fired his National Development Planning minister Lucky Mulusa in January and Information minister Chisimba Kambwili, who was sacked in November last year.
Mr Kambwili is currently facing corruption charges in court, a case he describes as politically-motivated.
Critics of President Lungu have raised concerns over what they see as "narrowing of freedoms" including the crushing of dissent.
Mr Lungu is seeking a "third term" in office, a matter which is before the country’s Constitutional Court.
His eligibility for the 2021 election is being challenged by those who argue that he is serving his second and final term, and cannot stand for re-election.
Critics say the period he served after the death of President Sata in 2014 counts as his first term.