Time was running out for the ILVA steel mill in southern Italy on Monday, following an order from Italian prosecutors for shutdown operations at the site to begin within five days.

The plant, the biggest in Europe, has been running at reduced capacity since magistrates sent in special administrators in July and ordered it be closed after an inquiry into damning environmental reports which revealed high cancer rates in the region.

The facility, which employs about 12,000 workers, has become the site over recent months of clashes between demonstrators fighting to keep their jobs and environmentalists who are demanding the site be cleaned up.

On Saturday, the prosecutors called on ILVA head Bruno Ferrante to ensure that the most polluting parts of the site were shutdown within five days.

Environment minister Corrado Clini slammed the order as "impossible to fulfil" because of the complexity of both the site and the shutdown process.

ILVA, part of the Riva steel group, has become the face of a heated debate in Italy over the need to protect jobs in Italy's southern region, which has long suffered from high unemployment and has been hit hard by the recession.

"ILVA still has not done anything, it still has not presented a credible plan for a clean-up," said Nichi Vendola, governor of the Puglia region.

"It is playing a dangerous game. It is not possible that a group which has filled its pockets with b can kill off a factory which maintains 20,000 families," he said, according to Italian media reports.

Studies found that the deadly emissions leaking from the plant were causing cancer rates which were 15 to 30 percent above average from 1995 to 2002.

In September, Judge Patrizia Todisco rejected the management's proposal to invest 400 million euros ($520 million) to modernise the plant, saying ILVA had already promised to carry out the same overhaul in 2003-2004.

The environment ministry has been battling to keep the site open, warning that Italy will lose out to competitors in Europe and China if the mill closes.

"I'm not at all optimistic. The priority for the moment is to make sure production does not stop," said UIL trade union secretary, Luigi Angeletti.