The late Lavender passed on under mysterious circumstances on August 22, 2020, amid allegations that he was murdered.
He was a popular ward 4 councillor under the opposition who had been in office for 13 consecutive years.
At the weekend, his brother Johannes joined the ruling party, claiming it was his constitutional right to do so.
Johannes was among eight opposition members paraded at a rally addressed by the ZANU PF national chairperson Oppah Muchinguri at Chikangwe Stadium in Karoi at the weekend under operation Tadzoka Kumusha.
Chiwaya said he endured public mockery over abandoning the opposition for the ruling party. He said:
Everyone has his or her constitutional right. In our Constitution, there is a Bill of Rights that says everyone has a right to freedom of association that must be respected. I am not a sellout. This is my personal consideration and conviction to be part of Zanu PF. I am warning those that have labelled me a sellout that I will not accept it any longer. I will take legal action.
Johannes was among the top youth leaders under the late MDC-T leader Morgan Tsvangirai.
After the opposition split, he remained on the fence while his late brother Lavender aligned himself with the then MDC Alliance which was led by Nelson Chamisa.
Their brother Solomon, however, joined the MDC-T formation led by Thokozani Khupe.
At the Karoi rally, Johannes appealed to the government to help him acquire a plot.
More: NewsDay Zimbabwe