He has served and led the Party in various capacities since joining ZAPU in 1962 and ZANU at its formation in 1963, and has always been a proponent of unity of the country and of ZANU PF and PF ZAPU cadres within the party and the military, with active participation in the formation of the Patriotic Front in 1976 and the Unity Accord in 1987. He was sent by then ZANU for military training in China, at the Nanjing (Nanking) Academy in 1963, returning in 1964 and almost immediately entering the country as a trained military commander, leading the first trained guerrilla group to cross the Zambezi River from Zambia. He attended the formative ZANU Congress in Gweru (Gwelo) in May 1964 as a youth leader. He divided his group into two units to undertake the first sabotage activities in Southern Rhodesia since the First Chimurenga in the 1890s, and trained the famous Crocodile Commando that mounted roadblocks and petrol bombings in Chimanimani the same year. He was arrested in 1965 and spent the next decade in prison, when many party leaders were in detention, restriction or prison.

With guidance from the party to use the time of incarceration to advance education, he concentrated on his studies, completing O and A levels and the intermediate part of a law degree, and supported other party activists in prison, until he was released in 1973 and deported to Zambia where his parents lived. On his return, he carried messages from party leaders to senior officials and leaders of the United National Independence Party in Zambia. Resuming party activities in Zambia, he wanted to go to Mozambique to join the war again, but he was advised by the party Chairman, Herbert Chitepo, and the ZANLA Commander, Josiah Tongogara, to finish his studies first.

He combined party activities with law studies at the University of Zambia for two years and then did articling with a Zimbabwean lawyer in Lusaka. He spent part of this period as a legal assistant in shuttling between party leaders who were imprisoned in Kabwe and Kamwala in Zambia. He went to Mozambique in 1977 and was elected at the Chimoio Congress of the party to be Special Assistant to the President, thus the head of civil and military security, deputized by Sheba Gava (Vitalis Zvinavashe) throughout the Year of the People (1978), and the Year of the People’s Storm (1979).

In this capacity, he resumed party activities, with responsibility for the security of the president and party in the last stages of the war and participated in all negotiations including Malta I and Malta II, until the war had spread throughout the country, causing the colonial power to host negotiations with the liberation movement, the Patriotic Front, led by Robert Mugabe and Joshua Nkomo, at Lancaster House in London in the latter half of 1979. An agreement was signed on 21 December 1979 and the ceasefire took effect a week later, on 28 December. He led the first group of 23 party officials to return to then Salisbury on 4 January 1980. He continued to have responsibility for the security of the party and president through the 1980 elections at the end of February, the announcement of election results on 4 March, and the complex transition to Independence on 18 April 1980.

From 1980 to 1982, he retained his pre-independence responsibilities as head of security, becoming Secretary for Finance in the party in 1982, a position he held until 1992, when he was chosen by the party to head its operations as Secretary for Administration for the next five years. He served as Secretary for Legal Affairs from 2004-2014, and became Vice-President of ZANU PF from the party Congress in December 2014 until November 2017.
On 19 November 2017, he was elected by the Central Committee as President and First Secretary of ZANU PF, pending Congress in December.