24 July 1980
The biggest strike by the migrant municipal workers took place in Johannesburg, the largest and most industrialised city in South Africa. The strike involved over 10,000 African municipal workers. Apart from a wage crisis, the strike was centered around the migrant labour system under apartheid. In addition to restricting the freedom of mobility of the migrant worker and his family, it further created additional difficulties within the field of trade union organisations. Migrant workers were not allowed to join trade unions, as they were not representing a stable and permanent labour force. These workers demonstrated their advanced class consciousness and willingness to take militant action despite the possible consequences during the strike.  
References

South African hotels,(2013),'A history of Apartheid in South Africa from 1930 until 1960', From South African hotels, 17 April,[Online], Available at www.south-african-hotels.com [Accessed: 24 July 2013]|

The Citizen,(2011), 'Municipal workers to strike', From The Citizen, 05 August [Online], Available at www.citizen.co.za [Accessed: 24 July 2013]