IF OIL, gas and mining firms revealed their payments to governments, campaigners say, it would be easier to expose bribe-payers—and bribe-takers. Activists rejoiced when they got a provision requiring firms to publish payments per project included in the ragbag Dodd-Frank corporate-reform act in 2010. “We thought we had blown up the Death Star,” says Ian Gary of Oxfam America, a charity.

But, he concedes, the empire struck back. A year later, amid increasing objections from the oil industry, the Securities and Exchange Commission has yet to finalise the rules that the law stipulates for extractive-industry companies listed in America. The American Petroleum Institute, an industry group, is now threatening to sue the SEC, claiming its cost-benefit sums are wrong.

In response, campaigners are pressing their case anew, with public stunts and an advertising campaign. Their efforts are echoed elsewhere. In October the European Commission proposed similar rules, but covering forestry and unlisted firms too. These should pass: Britain and France, with the largest extractive industries in Europe, support them. Indonesia and Hong Kong have tightened their reporting rules.

Business has many objections. The new rules are overly intrusive. In countries such as Angola, Cameroon, China and Qatar they may clash with local secrecy laws. They can cause security problems, discourage investment in poor countries and disadvantage law-abiding firms which must compete with unscrupulous rivals. The rules are too vague: how do you define a “project”? And what is a “payment”? Does it include, for example, a $50,000 monthly rent for an expat manager's housing, paid to a landlord who happens to be a well-connected local official? The result will be confusion, not clarity.

But businesspeople struggle to produce examples of how local restrictions on publishing confidential contract details could clash with transparency requirements elsewhere. Contracts in developing countries typically have a clause permitting disclosures that are required by the company's home country and stock exchange. Nor does greater disclosure seem to hurt competitiveness. In 2011 Angola awarded several new deepwater oil concessions to firms covered by Dodd-Frank. No oil company has so far cited increased openness as a material risk in its SEC filings.

The expense has been minimal for the few, such as America's Newmont Mining, that already provide country-level reporting (none yet breaks the numbers down project-by-project). Exxon says that the new rules would cost $50m. That is a lot of money, to be sure, but only 0.1% of last year's profits. Companies already collect for internal use the data they are being asked to make public.

A stronger argument is about the difficulty of defining a project. The American authorities collect information about individual leases and licences, which is where the terms fixing payments are usually set out. Corruption fighters would find such details useful. They used them in a legal battle to trace energy revenues snaffled by friends of Myanmar's leaders.

Some investors are clamouring for change too. Paul Bugala of Calvert Investments, which manages $13 billion, says it would help him to assess political and regulatory risks and would benefit share prices in the long run. Polled by activists, investors managing $1.2 trillion, mostly on behalf of pension funds, backed America's proposed rules. It is “patronising” to say that shareholders would find more information confusing, says Joseph Williams of Publish What You Pay, a pressure group.

Some fear that the new efforts could undermine a ten-year-old multilateral process, the Extractive Industries Transparency Initiative (EITI). Campaigners have long complained that it lacks bite: it is voluntary and data standards vary among the 35 countries that have signed up. Some suspect that the firms on the initiative's board sing its praises only because they can ensure it stays toothless. But Diarmid O'Sullivan of Global Witness, a campaigning group, says the new efforts are unlikely to do harm. “We are a long way from having too much information,” he says.

Oil companies are in a bind. Payments that may make sense in narrow business terms may well look bad under public scrutiny. Yet going to court to keep such deals hidden could yet become a public-relations disaster.