Last Wednesday saw transnational mining giant Glencore hold a glitzy “investor day” event in London.

It also happened to be UN Human Rights Day.

Glencore’s human rights record is nothing to boast about. In Colombia, a group of former army officers have linked the firm to paramilitaries responsible for murdering trade unionists — with the killers actually training on a site located inside a Glencore mine.

The company is accused of massive violations of health and safety laws in Colombia and Peru, denying fair payment for overtime and severance packages in those countries as well as South Africa and the United States and refusing to rehire trade union members and evicting their families from company housing in Australia.

Glencore is a global bully.

That’s why Workers Uniting — the three-million-strong international union founded by Britain’s Unite and North America’s United Steelworkers — marked the day by holding a protest outside Glencore’s London HQ.

Together with Unite assistant general secretary Tony Burke, Texan miner and union chief negotiator Jessie Green handed in a letter of protest on behalf of 450 workers who have been locked out of the Sherwin Alumina plant there since October 11.

Green, a power systems operator who’s done 27 years at the plant, says it’s a tough place to work.

Staff work 12-hour shifts, supposedly on a four-day on, four-day off system, but overtime — frequently compulsory — adds 35-50 per cent to their hours.

The Mine, Safety and Health Administration records 35 employees at Sherwin Alumina being seriously injured in the first six months of 2014.

Its non-fatal days lost injury rate is calculated at 5.25, more than twice the US average and 72 per cent higher than at other alumina refineries.

“The accident rate at our plant is higher,” Green says. “The job is very physical, so you get repetitive strain injuries and shoulder injuries from swinging sledgehammers, plus you get slips and trips since production is prioritised over keeping the place clean.

“I’d put the higher level of accidents down to the hours people are working — we’re short-handed and there’s too much compulsory overtime.”

He remembers a colleague who fell into a chemical tank while cleaning it.

“The liquor splashed his eyes. He was almost blinded.”

Another worker was on a ship docking to offload raw materials at the plant’s port.

“The ship tightened on a line when it should have been loosened. He was thrown six feet in the air and fell flat on his back. That put him out for a few days.”

Even so, it was not poor safety standards that led to the firm locking out its workforce, but their refusal to stomach a management attack on their pay, pensions and benefits.

It’s not the first time bosses have demanded renegotiation of their conditions — when Glencore bought the plant in 2007 a renegotiation swiftly followed.

“The big change then was that they insisted we pay for healthcare,” Green recalls.

“Under Reynolds Metals (the previous owner), wages stayed low but we didn’t pay for health insurance.”

Currently staff at the plant pay $100 (£64) a month from their wages for their health insurance, but this year

management insisted on a raising that by 75 per cent.

“Negotiations were expected,” Green says. “Our old contracts expired in July, but then they extended them up to September for the talks.”

But workers weren’t expecting the proposals bosses put forward. Apart from the health insurance rise, these include abolishing overtime pay for hours worked on scheduled days off, replacing a pay rise at the end of an employee’s first year with a non-consolidated $1,500 bonus, scrapping health coverage for all retired staff who qualify for Medicare (the federal US health plan for pensioners) and attacking pensions.

“We told them: ‘If you don’t want to give us healthcare when we retire, start a fund’,” Green tells me. “But they weren’t happy with that.”

Health insurance is further attacked by eliminating employer contributions to the voluntary employees’ beneficiary association (Veba).

In the US, where the lack of an NHS means citizens have to buy health insurance schemes whose level of coverage varies, some firms operate a Veba fund to help with “out-of-pocket” expenses incurred by patients and “deductibles” which are not covered.

Initially the company wanted to get rid of the defined pension plan entirely. After tough bargaining by the union, it settled for refusing to increase pensions for current employees and abolishing them for new ones.

“This was their last, best, final offer. We took it to the members — we didn’t want to, but we took it to them — and they voted it down 98 per cent.”

There had not been a labour dispute at the plant for over 30 years. Texas is a “right to work” state, which meant that staff had a no-strike agreement in place, while the company was not allowed to lock them out — while they had contracts. But the contract extensions expired on September 30, and on Octo

ber 11 — despite the union still sitting round the table for talks — the firm locked them out and called in the scabs.

So what’s behind bosses’ penny-pinching? Is the company in trouble?

“Trouble! Last year we had record production — we produced more alumina than ever before in our 61-year history,” Green points out.

“Our plant alone made a profit of over $38 million. And Glencore…”

He shakes his head and laughs. Glencore is ranked 10th in the Fortune 500 list of the world’s largest companies. Its 2013 revenue was $233 billion.

“The plant’s doing well. Natural gas costs are down.”

The firm pointed this out back in 2011, explaining that using relatively low-cost US natural gas as its energy source gave it a competitive advantage compared to most other alumina producers worldwide.

“This development in conjunction with contractual arrangement for other raw materials that are linked to LME prices for aluminium has allowed Sherwin Alumina to significantly improve its position on the global cost curve.”

“Our position was, profits are up, y’all need to pay us more,” Green says.

Sherwin didn’t see it that way, though — and Green suspects he knows why.

“You look at what Glencore does around the world, and when they take something over they try to break the union. It’s business as usual for them. They’re trying to break United Steelworkers at the plant.”

His suspicions were fuelled by the way the company had clearly planned for the lockout.

“We approached the negotiations in good faith,” he says. “Did they? Three months before, they ordered us to train some supervisors. One month before, new staff were brought in from a firm out of state, and trained by those supervisors.

“It’s common practice. Sherwin said they were seeking a fair and equitable agreement. They must have been lying.”

Since the lockout, staff have mounted a picket line at the plant gates.

“It’s been peaceful, though immediately before the lockout they hired some guards from somewhere who were in

the plant striding around policing us.

“We held a rally on the water with a dozen boats, mounting a picket where the delivery ships come in. They weren’t ready for that — ‘That’s illegal, get out of here!’ — but TV crews were there and we got coverage.

“We’ve got a lot of public support too with Adopt an Angel — kids whose fathers have been locked out might not be getting much for Christmas, so this was to get donations and support from fellow trade unionists.

“Folks saw that on TV and we started getting donations from them too.”

And United Steelworkers also took up the fight internationally alongside Unite and global union federation IndustriALL.

“Last month IndustriALL held a meeting of 32 representatives from 14 countries in Sao Paulo and we mounted a protest over Glencore violations in all those countries.

“Now we’ve taken the protest to their London investors’ day. And three days before I got on a plane to come to London, we hear they want to reopen negotiations. Right now we’re negotiating with them. Is it in good faith? I don’t know if they’re serious. Some of the things they claim to be offering are things we already have.

“We didn’t go in there asking for the world. We just didn’t want them to take what we had.

“Glencore’s making money hand over fist. All we want is a modest pay increase and to keep our benefits and healthcare.

“I’ve worked 27 years in that plant. I’m close to a pension myself. It’s important to me, to all of us.”

The pressure has clearly rattled the firm, with the offer to reopen talks closely followed by a media release affecting to “welcome the opportunity” to respond to IndustriALL’s concerns.

Will the locked out staff return to their plant victorious?

“With the deep pockets Glencore has, I’d be lying if I said I was 100 per cent optimistic.

“But if we keep up the pressure, I certainly hope so.”