Thousands of African National Congress (ANC) Youth League supporters are expected to walk from the Johannesburg CBD to Pretoria on Thursday as part of an "economic freedom youth mass action".

After being denied permission to hold a vigil outside the Union Buildings on Thursday night, the league secured the Caledonian Stadium in Pretoria as a venue.

Tshwane metro police denied permission for the Union Buildings vigil due to security concerns. The presidency also declined because the site is classified as a national key point.

However, permission was granted for the youth league to march to the Union Buildings on Friday morning to hand a memorandum to the presidency.

The ANC expressed its support for the league's march. General secretary Gwede Mantashe said it did not see it as attack on the ANC government and was not linking it to the party's 2012 elective conference.

Youth league members were expected to march from Beyers Naude Square to the Chamber of Mines in Johannesburg, the Johannesburg Stock Exchange in Sandton, and then to Pretoria.

On Monday, youth league leader Julius Malema said there would be 1 000 youth league marshals, 500 police officers as well as private security company members to ensure the march was peaceful.

Police and the Gauteng community safety department said their officers were ready for any eventuality.

The last mass action by ANCYL members happened outside Luthuli House in central Johannesburg at the start of Malema's disciplinary hearing last month. Youth league members threw rocks, bottles and bricks at journalists and police, and burnt ANC flags and t-shirts with pictures of President Jacob Zuma printed on them.

The National Youth Development Agency (NYDA), Congress of South African Trade Unions, South African Municipal Workers' Union, South African Students' Congress, Congress of the People Youth Movement (CopeYM) and National Union of Metalworkers of South Africa supported the ANCYL's march.

The NYDA said the march raised salient youth development issues. It would not make a financial contribution towards the march, but called on the youth to participate.

Although CopeYM supported the march, it said it would not participate.

Not supporting the action was lobby group AfriForum, the Young Communist League, the South African Communist Party and the Communication Workers' Union (CWU).

The CWU said it would rather support the Young Communist League's job youth summit, which started on Wednesday, and ends on Friday.

Political analyst Steven Friedman said the league's mass action would test the support base of its leader Julius Malema ahead of the ruling party's elective conference next year.

Another analyst Aubrey Matshiqi said a multiplicity of political motivations were behind the league's march.

The march was taking place a day after testimony in Malema's disciplinary hearing was concluded. He and several co-leaders face charges of bringing the ruling party into disrepute.

ANC veteran Winnie Madikizela Mandela was the last to testify in his defence on Wednesday. Arguments were scheduled for November 3.