The ANCYL is a "necessary irritation" to the ANC, the league's deputy president Ronald Lamola said on Monday.
"And the young people of the ANC, you must never be apologetic about your role in the African National Congress," he said at the ANC Youth League's 68th anniversary celebrations in Thembelihle, Lenasia, south of Johannesburg.
"The ANC has achieved 100 years because of the many contributions of young people. It was young people who rendered South Africa ungovernable... It was young people who started the ANC."
He said the future of the ANC was "doomed" if creative and innovative leaders were not given space to grow within the organisation.
"We are not a group a cheerleaders and praise worshippers for the leadership of the ANC. We are a critical body of opinion and a preparatory school for the ANC," Lamola said.
"We must not shy away from calling for a new leadership in the Mangaung [conference]."
He said the ANC needed to be taken over by a "new generation" of leaders.
"Since its birth the youth league is a force for change in the ANC - this is not new," Lamola said.
"The reason why the youth league was formed was to change the ANC."
He said the party would elect new leaders at its conference in Mangaung in December.
"You must not be scared about those using discipline as a campaign tool for a second term," Lamola said, referring to a campaign to have President Jacob Zuma elected for a second term as ANC leader.
"Whatever platform they get they speak about discipline. They no longer speak about providing houses... or water to the people. Comrades, we must be told about the future of the country."
Lamola said the ANC was like a parent who disciplined a pupil without having seen their report card.
"You must be worried that you did not give birth to a proper child."
He criticised the country for having a "cosmetic" rainbow nation.
Arts and Culture Minister Paul Mashatile agreed with Lamola on "renewing" the ANC's leadership.
"We must renew our leadership and make sure when we elect leaders in Mangaung... we bring in the new generation of leaders.
"But we are saying today... we need radical change so that in 18 years or 20 years of democracy our people can look back and say 'we have a better life'."
He said the ANCYL was hosting its celebrations in Thembelihle instead of Sandton so it could "see their people".
"At the conference, we must adopt radical policies. Let us go there and renew the organisation. It [the African National Congress] must remain rooted amongst the masses of people."
He said the country's future was in the league's hands.
"We are saying to our young leaders: 'It is your responsibility to make sure you bring about change... So that people can have a better life'."
Earlier, Gauteng ANCYL secretary Ayanda Kasa-Ntsobi said the ANC needed "decisive leadership that was not afraid of its people".
She led the crowd in vocally supporting Deputy President Kgalema Motlanthe and Sports Minister Fikile Mbalula, who were reportedly running for the positions of ANC president and secretary-general respectively.
The crowd sang songs in favour of Motlanthe while rolling their hands in the gesture used to call for the substitution of a soccer player.
Some held up one finger, representing one term for Zuma.
More than 500 people attended the celebrations. A three-tier cake, decorated in the ANC's green, black and gold, and the words "economic freedom in our lifetime" was cut and distributed after the speeches.
The children in the audience got cupcakes.