Mayfair Gold, whose largest shareholder is Carson Block's Muddy Waters Capital, has secured fast-track permitting status for its Fenn-Gibb gold project in northern Ontario, potentially accelerating development of the mine, according to a report by Bloomberg.

The project has been selected for Ontario's "One Project, One Process" initiative, which aims to reduce government review timelines by 50%. Mayfair expects to make a construction decision as early as 2028, with production targeted for 2030. Shares in the Toronto-listed company rose as much as 13% following the announcement.

Fenn-Gibb contains approximately 4.3 million ounces of indicated gold resources and is expected to require C$450m in initial development capital. Mayfair recently secured a proposed financing package of up to C$310m ($222m) from Macquarie Bank to support the project.

Block, best known for his activist short-selling campaigns, became a director of Mayfair in 2024 following a successful proxy battle to replace the company's board. The same year, he launched an investment fund targeting long positions in metals and mining companies, expanding beyond the bearish strategies traditionally associated with Muddy Waters.

The development highlights Block's growing exposure to the mining sector as Ontario seeks to accelerate domestic resource projects amid heightened global trade tensions. Fenn-Gibb is the fourth project selected for expedited permitting under the provincial initiative, alongside developments backed by major mining companies including Kinross Gold.