The union has also called for the regularisation of 4,000 casual employees, who have been working in the Department of Telecommunications (DoT) and BSNL for 5-10 years.

'They have been denied regularisation, citing a Supreme Court judgement. But other PSUs (public sector undertakings) and government departments have continued to regularise casual labourers,' Namboodiri said.

Meanwhile, about 10,000 engineers at BSNL started an indefinite strike Tuesday, demanding absorption of officers who were deputed from DoT.

The management could not be contacted for comments despite repeated attempts.