Finance Minister Pravin Gordhan criticised state-owned enterprises for obstructing the government’s objectives through corruption, as he addressed the 10th conference of the National Union of Metalworkers of South Africa (Numsa) on Monday.

“Not all boards are working for us…They must work for South Africa rather than their friends and connections, and you know what I am talking about,” he said to applause from delegates, after giving an overview of the country’s economic challenges.

Gordhan singled out Eskom’s reluctance to conclude approved contracts with independent power producers for renewable energy, saying: “Eskom can’t seem to make up its mind if it is going to sign the contracts government told it to sign.”

Gordhan has publicly accused Eskom of failing to cooperate with National Treasury’s review of the utility’s coal contracts with the Gupta family’s Tegeta Exploration and has appeared to counter Eskom’s insistence that it needs to procure nuclear energy as alternative sources were not sufficiently reliable.

Introducing Gordhan as a guest speaker, Numsa secretary-general Irvin Jim said he had been invited as National Treasury was a “centre of power” in South Africa, then reiterated the trade union’s opposition to neo-liberalism.

Gordhan teased that he admired Jim’s unfailing consistency, but that the world had “moved on” in ideological terms. Labels, including neo-liberalism, should be left aside in favour of finding common purpose as a country, he said.

“I’m not a neo-liberal, you can call me that, it doesn’t make a difference to me. I didn’t grow up that way. We need to deliver the promises we make to our people. Don’t label people, it hasn’t helped one bit to get things done.”

He added that ideological dismissal of ratings agencies was pointless as the impact of dwindling growth on revenue made it imperative that the country could convince them, and thereby lenders, that it remained a credible creditor.

Gordhan warned that the election of Donald Trump as the president of the United States and Britain’s decision to leave the European Union could bring further economic difficulty for South Africa in 2017 by affecting trade agreements. They could also see the rise of right-wing political parties throughout Europe.

Numsa was expelled from Cosatu in November 2014 and is mulling the formation of an alternative labour federation.