More than 1.3 million public servants affiliated to Cosatu and the Independent Labour Caucus will go on strike on Tuesday after wage negotiations failed, the unions said on Friday.

General secretary of the SA Democratic Teachers Union (Sadtu) Mugwena Maluleke told media in Midrand the unions had rejected government's offer on Thursday.

Workers will march and demonstrate through the country.

"[It will] lead to a complete shutdown of the public service," he said.

"National marches will take place in Cape Town and Tshwane in Pretoria as well as provincial marches in all the cities in the whole country."

The unions rejected the government's revised wage offer of a seven percent increase and a R630 housing allowance, as well as a 1.5 percent fixed pay progression.

The unions were demanding an 8.6 percent wage increase and a R1000 housing allowance, backdated to April 1.

Maluleke said the march in Cape Town on Tuesday will start at 10am and will lead from Keizersgracht Street to Parliament, to end at 3pm. In Pretoria, the march will start at 8am at Schubart Park to the Union Buildings. It will end at Schubart Park at 11am.