Republic Resumes in Adelaide is getting hit from workers in Whyalla, who fear for their jobs if Citibank breaks up the Australian empire of British billionaire Sanjeev Gupta.

An application was lodged in the NSW Supreme Court on Tuesday to wind up the operations of two companies, including OneSteel Manufacturing which runs the steelworks and employs more than 1,200 workers.

Another 4000 jobs in Whyalla and the region rely on the steel mill operating.

The move comes after the collapse of one of the major lenders to Mr Gupta’s GFG Alliance, Greensill Capital.

Greensill was placed in the hands of administrators Grant Thornton after global wealth manager Credit Suisse froze $US10 billion ($13.1 billion) worth of investment funds that it relied on.

Citibank filed the action on behalf of Credit Suisse, and it follows a similar application by Citibank in London. The case is set for a directions hearing on May 6.

The Australian businesses are performing well due to strong steel and iron ore markets.

Even though GFG Alliance’s Australian Mining and Primary Steel business does not have any financing with Credit Suisse, the Whyalla Steel works can still be wound up as Gupta owes billions to Greensill Capital, which in turn owes billions to a range of creditors.