Unionised workers in the glass sector will down their tools on Monday, says the General Industries Workers Union of SA.

The union, which is an affiliate of the South African Federation of Trade Unions, on Sunday evening issued a statement indicating that close to 1 000 workers will be striking at glass companies including Nampak Glass, Consol Glass and PG Glass, among others.

Workers are demanding an 8.5% increase across the board. Further, the union wants labour brokers' workers to be made permanent after three months by client companies. The agreement must be in effect for one year and must cover all union members, the statement read.

According to the union, the employers' association is offering a 6.75% increase and want a two-year agreement.

"Our members have taken the route of strike action because their living standards and that of workers at large are constantly being eroded by the unceasing increases in the costs of living… The strike is therefore a means of defending and protecting workers' current living standards," the statement read.