Human Services General Manager Hank Jongen has warned benefit claimants will suffer serious delays and disruptions when Human Services’ staff go on strike on Monday next week.

Mr Jongen said the Community and Public Sector Union (CPSU)-led 24-hour strike, which will affect Centrelink, Child Support and Medicare services in his department, would punish those relying on government support, although contingency plans were being put in place.

“The lead up to Easter is always an extra busy time because our staff are already working hard in a short week to ensure people are paid before the public holidays,” Mr Jongen said.

“This action further stretches our resources and punishes people who need government support. We are concerned the union is encouraging its members to take counter-productive industrial action, which will inconvenience people across Australia, including some of the most vulnerable people in our community.”

There will be fewer staff manning the phones and working in service centres on Monday with longer wait times predicted.

Mr Jongen said: “Our advice to customers is – if you don’t need to contact us urgently, consider delaying your visit or contacting us another time. Alternatively, use self-service options to do your regular business with us. This will ensure our available staff are able to assist those most vulnerable or with urgent business.”

He suggested customers who needed to update their earnings go online using myGov and Express Plus mobile apps or phone self-service so they were paid on time but he added that he was confident people would receive their usual payments and pledged that the department would do its best to minimise service disruptions.

But CPSU National Secretary Nadine Flood hit back, saying: “It’s a bit rich for Department of Human Services’ bosses to say this strike will inconvenience families when they are trying to strip family-friendly working conditions from their own staff.

“We have working women in Centrelink and Medicare telling us they’d have to give up their jobs at DHS if this agreement went through, with proposals like workers being forced to work anywhere in a major city, different hours and days of work or even split shifts.

“Our union has put out a sensible, reasonable outcomes position with workers willing to agree sensible changes to agreements, including in DHS, but the Turnbull Government is still refusing to move on key issues like stripping essential family-friendly rights and conditions out of agreements, preventing any improvements like domestic violence leave and no recognition of the impact of a two-year wage freeze.

“The reality is that these workers have been fighting for two years to get a fair deal where they can keep those important rights and that’s why they’re striking.”

DHS staff have voted down two government offers so far, the most recent being in February when almost 80 per cent of staff voted to reject it.

The March 21 strike, which also involves public servants from a number of Commonwealth government departments and agencies, including the Australian Tax Office, Defence, the Bureau of Meteorology and the Department of Prime Minister and Cabinet, is a direct response to the ongoing public sector industrial relations deadlock.

Around 80 per cent of the Commonwealth’s 135,000 public servants have been waiting up to two years to sign new enterprise bargaining agreements. Although the union and the government have moved closer together on pay, changes to rights and conditions have proved the more intractable subject of negotiations.

The Departments of Immigration and Border Protection (DIBP) and Agriculture will strike from Thursday March 24, with rolling strikes at airports beginning on March 22 and continuing for several weeks, across the Easter and school holidays.