Addressing a news conference Friday at the party's Harvest House headquarters, MDC-T spokesperson Douglas Mwonzora said the National Council resolved to suspend Mangoma following accusations he violated four sections of the party's constitution.
Mwonzora alleged Mangoma had also abused party funds by holding illegal meetings with party structures promoting factionalism.
Sources said Mangoma stormed out of the meeting shortly after the decision to suspend him was reached.
Mwonzora said all the 12 provinces of the opposition party voted unanimously to suspend Mangoma.
The MDC spokesman noted that Mangoma will appear before an independent tribunal to be announced in due course, which is composed of three lawyers.
He added that internal investigations conducted by an ad-hoc committee led by the party's organising secretary Nelson Chamisa into the alleged assault of Mangoma, allegedly revealed that the deputy treasurer general was not assaulted by a known party activist last month after a party meeting at Harvest House.
Mwonzora said video evidence, reviewed in Friday's National Council in full view of Mangoma, shows that the person who assaulted him was not in the structures of the party, adding the police have refused to take action on the video evidence.
Four MDC-T members have since been arrested and arraigned before the court on charges of assaulting Mangoma. They were released on bail this week.
Mangoma penned a letter to Mr. Tsvangirai recently detailing what he thought were the party's weaknesses, including Tsvangirai's himself and recommended the former trade unionist should quit his position to allow the party to renew its leadership and prepare for the 2018 elections following its crashing defeat to Zanu PF in the July 31 national elections last year.
The dossier was, however, leaked to the media and Mangoma proceeded to give interviews with the press despite a resolution of his party's National Council barring him from doing so.
As the party's secretary general Tendai Biti came out of the meeting, MDC supporters who were milling at the party's headquarters booed him and also sang songs denouncing Mangoma.
Biti is alleged to be in the same camp with Mangoma. He escaped the wrath of angry Tsvangirai supporters by jumping into the MDC-T leader's car.
The activists also sang songs praising Tsvangirai and chanted the party's slogans.
As the pro-Tsvangirai supporters continued to sing, anti-riot police then dispersed them, beating some of them in the process.
Passers-by were assaulted by the police while traffic passing through the MDC-T headquarters was diverted by the law enforcing agents.
Meanwhile, party secretary general Tendai Biti told a hastily arranged press conference that Mangoma’s suspension is null and void.
Biti said the composition of the National Council meeting that made the decision to kick out Mangoma was a nullity.
“We sat this afternoon but the events thereof are regrettable and I represent the views of many of us who are democratic and have suffered for this,” said Biti