A US politician has launched a campaign for more transparency in shareholder voting results involving using dual-class shares.

Sean Casten, a Democratic member of the House of Representatives, launched a bill this week that would direct regulators to mandate disclosure of how many votes cast at an AGM are Class B shares—those with extra voting rights—compared to Class A shares that function on the “one share, one vote” rule.

The move once again raises the issue of how company founders—those most likely to hold Class B shares—exercise their voting rights, especially if their opinions clash with the majority of ordinary shareholders.

In a statement, Casten says the Multi-Class Stock Company Voting Transparency Act would enable stockholders to understand how dual-class shares are “impacting their rights as shareholders”.

“Investors deserve to know whether the board’s response to the outcome of a proposal reflects the preferences of the majority of shareholders—or whether super-vote shareholders swayed the results,” he says.

Dual or multi-class shares are a bugbear for campaigners on both sides of the Atlantic.

In May, Railpen, a UK pension fund, called on Meta to disclose AGM vote results according to share class in a bid to reveal the influence of founder and CEO Mark Zuckerberg.

Writing on LinkedIn, Railpen’s head of stewardship, Caroline Escott, said: “This is a straightforward request, which would significantly improve the information both company boards and shareholders receive on the views of the whole shareholder base, in turn boosting trust and supporting long-term value creation.”

Railpen isn’t alone in its call for more disclosures. In an article for the Harvard Law School Forum on Corporate Governance, researchers at Morningstar wrote: “Given the important role of advisory shareholder voting in shaping corporate governance practices, we believe companies with dual-class share structures should be required to disclose proxy voting results disaggregated by share class.”

In Meta’s case, the proposal said: “The outsize impact of Class B votes means that voting outcomes may not reflect the concerns of the broader shareholder base.”

This month, the Norwegian sovereign wealth fund expressed its concern about shareholder rights, citing dual-class shares as an issue. Carine Smith Ihenacho, the fund’s chief governance and compliance officer, told Reuters: “We are concerned about shareholder rights generally. We are concerned because we’re seeing it’s been diminished in many markets, not just the US, but also in the UK, in Europe, in Hong Kong even.”

Jack Grogan-Fenn at shareholder advisors Minerva writes this week that the Casten proposal reflects “growing scrutiny of governance models that concentrate power in the hands of founders, executives and other insiders”.

He adds: “For investors evaluating future IPOs and existing dual-class companies alike, insight into how voting power is exercised may become an increasingly important governance consideration.”