While ANC national chairperson Gwede Mantashe and EFF leader Julius Malema were given the platform to speak on behalf of their political organisations, the ANCYL was not included on the programme.
ANC head of elections Fikile Mbalula was instead allowed to speak “on behalf of young South Africans” - which has outraged the league.
On Sunday, Nkabinde said their sidelining showed the lack of respect the ANC leadership had for its youth wing.
“That was definitely a sign of the extent to which the ANC Youth League is undermined by the ANC leadership. You cannot have a funeral for Mama and not give us space. Mama has been known to be a leader who was closer to young people during her activism,” he said.
“For me, this was a clear vote of no confidence in the ANC Youth League, and the ANC needs to explain to us why they sidelined us from paying a tribute to Mama.
“It is clear that the ANC does not take the leadership of the league seriously,” Nkabinde said.
His complaints come days after ANCYL president Collen Maine admitted having met the controversial Gupta family, which has been accused of looting the state by using their influence with political leaders and heads of state-owned entities through their ties with former president Jacob Zuma.
Speaking at Madikizela Mandela’s memorial service in Potchefstroom last week, Maine said he was introduced to the Gupta brothers - who have since fled the country - by North West Premier Supra Mahumapelo.
Maine’s admission, in which he called on ANC supporters not to support him should his association with the Guptas result in him being prosecuted, has pitted the league’s leadership against one other, with deputy secretary-general Thandi Moraka calling for his removal.
Nkabinde said the revelation by Maine was a result of the meddling of the ANC leadership in ANCYL matters, including its elective conferences.
Maine was elected ANCYL president at Gallagher Estate, Midrand, in 2015, with the backing of the so-called ANC premier league, which included Mahumapelo.
Said Nkabinde: “Even though I think it was incorrect to do that in public, but I don’t blame him (Maine). I would be the last to blame him, because as an official myself, I know how ANC leaders have always tried to capture the league for their business and political interests. These are the results of Gallagher. They (ANC leaders) try and capture certain individuals within the leadership of the youth league.
“This admission by Maine shows that he is tired of being captured by Mahumapelo and wants to regain his independence and respect,” he said.
Nkabinde said he would stop the capture of the league by unscrupulous ANC leaders should he be elected Maine’s successor when the organisation holds its conference this year.
ANCYL KwaZulu-Natal chairperson Kwazi Mshengu said Maine should answer to allegations that he had also apologised for campaigning against President Cyril Ramaphosa ahead of the ANC’s national conference in December.
“It has not only reflected badly on him as youth league president, but cast doubts on all of us as leaders of the youth league,” said Mshengu.
He said Maine had led the youth league to believe that the reports of him benefiting from the Guptas were a witch-hunt against him.