JERUSALEM, Feb 26 (Reuters) - Israel's main labour union threatened on Thursday to shut down a large part of the economy just days before a parliamentary election unless one of the largest companies in the country reverses a plan to reduce its workforce.
The head of the Histadrut labour federation said a weeks-long dispute with potash maker Israel Chemicals (ICL) reflected wider problems and would be expanded into a general strike in all of southern Israel unless the job cuts are nulled.
"We need to cause shockwaves here," said Avi Nissenkorn, whose federation represents hundreds of thousands of public sector workers, in an interview with Army Radio.
ICL, a maker of fertilizer and speciality chemicals, is Israel's second-largest traded company and is controlled by conglomerate Israel Corp.
Opinions polls show a tight race ahead of the March 17 election, campaigning for which has been dominated by economic issues like high living costs and workers wages.
Prime Minister Benjamin Netanyahu's office would not comment on the threatened general strike.
Nissenkorn accused the government of neglecting Israel's arid south -- roughly half the country -- and instead focusing economic support on commercial centres near Tel Aviv.
Tens of thousands of workers from government offices and private sector business would stay home if the strike goes into effect on March 12 as planned, the Histadrut said.
Nissenkorn called on the government to wield its "golden share" in ICL -- one of the top three suppliers of the crop nutrient potash to China, India and Europe -- to prevent the lay-offs.
ICL, which has exclusive rights to mine minerals from the Dead Sea, said it was determined to implement an efficiency plan that includes cutting 140 of 900 jobs at its bromine unit and 140 of 1,250 at its primary potash-producing Dead Sea Works.
The bromine unit has been closed since workers left their posts at the start of the month. Employees at the potash plant joined the strike a couple of weeks later.
ICL declined to say how much the strike had affected its business and accused the workers' groups of using "violence, aggression and brutality". "ICL's management will not allow the committees to take over the factories," it said in a statement.
The strike had been planned to coincide with the election to try to gain more political support, the company said. (Editing by Catherine Evans)