The strikes in the service and the metal and engineering sectors, especially, have exposed cracks in South Africa's trade union movement.
This has thwarted efforts to build unity and inter-union solidarity between affiliates of the Congress of South African Trade Unions (Cosatu) and independent trade unions.
In the metal and engineering sector, the National Union of Metalworkers of South Africa (Numsa) and Solidarity clashed towards the end of their four-day strike recently when Solidarity members accepted the industry's wage increase offer of 9% for the lowest-paid workers and 8% for skilled employees.
Solidarity's acceptance of the offer during separate talks with the employers, the Steel and Engineering Industries Federation of South Africa, angered Numsa's leadership. Its leaders felt Solidarity should have informed them before signing the deal.
Both unions had jointly participated in the wage negotiations in the bargaining council and during strike actions in South Africa's major cities.
'White racist union'
However, Solidarity's decision to clinch the deal with employers prompted Numsa president Mtutuzeli Tom to attack the union. He accused it of being a "white racist union".
Said Tom: "The metal industry in South Africa remains largely untransformed through racism management which is supported by the privileged positions of Solidarity members in the industry. We are prepared to co-operate with them to the extent of them changing their racist mindset."
Solidarity spokesperson Jaco Kleynhans said it was important to work with Numsa in the bargaining council because it was a "strong organisation" and the biggest union in the sector. Numsa has about 150 000 members of the 260 000 workers in the sector.
But he said it was unfortunate that Tom had launched a racial attack on Solidarity.
"It is sad that someone from the top leadership of Numsa made such racial attacks that were not based on facts but on emotions.
"Solidarity will always strive to combine our demands with Numsa during negotiations in the bargaining council for the interests of workers in the sector. If we're split during negotiations, we'll be giving employers an advantage to divide us further," he said.
'Whites only'
Solidarity was established from the previous "whites only" unions in the mining and steel sectors. Most of its members are skilled white artisans, engineers and technicians, while most Numsa members are unskilled black workers.
However, the differences between the two go beyond the racial composition of their members. Ideologically, the unions share different views on the crucial topic of affirmative action.
Solidarity has consistently called for a moratorium on affirmative action (AA) while Numsa has repeatedly rejected this call.
Solidarity last week slammed the "labour department's external audit on AA which claimed that 60% of appointments and promotions in the workplace were white.
In the past, Numsa's affiliate mother body, Cosatu, has hit back at Solidarity when it attacked government's AA policies. Last year, Cosatu lambasted Solidarity's campaign against AA saying it was "anti-black" and intended to speak solely for those "white workers who were beneficiaries of the racist whites-only job reservation policy".
Divisions emerge
Divisions also emerged in the public-sector strike between Cosatu affiliates when the latter's second-biggest public-sector affiliate, the National Education Health and Allied Workers' Union (Nehawu), pulled the plug on the longest public-sector strike in South Africa's history when it accepted government's wage increase offer of 7.5%.
Nehawu's decision sowed divisions among Cosatu affiliates and pitted them against one another.
Government took advantage of the lack of unity among Cosatu affiliates and tabled its final offer of 7.5% at the Public Service Co-ordinating Bargaining Council, ending the crippling 28-day strike.
Other unions such as the South African Democratic Teachers' Union, the National Professional Teachers' Association and the Public Servants' Association confirmed the cracks when they stood firm on their 10% wage increase demand although most of the 17 striking public-service unions had already signed the deal.
While the relationship between unions and employers in the metal and engineering sector has improved, government's relations with public-sector unions are said to be strained after the union got only a 7.5% wage increase instead of the initial demand of 12%.