Mining explorer Heron Resources has been forced to hold a spill of its board of directors after suffering a shareholder revolt at its annual general meeting.

Heron suffered a so-called “second strike” at the meeting on Friday, with almost 70 per cent of votes cast against the company’s remuneration report.

The company, which is focused on developing its Woodlawn zinc-copper project, south of Goulburn in NSW – will now need to call a spill meeting within 90 days.

It suffered a first strike a year ago.

A strike occurs when less than 75 per cent of shareholders vote in favour of the company’s remuneration report.

In a statement, Heron said the vote against the company at Friday’s AGM had been led by Canadian investment group Sprott Inc, which brought a more than 10 per cent stake in the company from BHP Billiton in August.

Sprott is looking to have three nominees elected to the board of directors at the spill meeting.

Heron said the company had cut executive and board pay 25 per cent in the past year and urged shareholders to vote against the Sprott bid.

“Shareholders should be careful to ensure control of their company does not inadvertently pass to a group acting in their own interest during the Board Spill Meeting,” chairman Craig Redhead said.

Heron shares were up one cent to 13.5 cents at 1040 AEST.