ST. JOHN'S, N.L. -- Environmentalists fearing the consequences of an oil spill in the Gulf of St. Lawrence, home to thousands of marine species, will have their say in court Monday.

Newfoundland and Labrador's offshore regulator will be in court in St. John's, N.L., as environmental groups argue an offshore exploration licence in the region was unlawfully extended.

The Canada-Newfoundland Offshore Petroleum Board granted Halifax-based Corridor Resources Inc. a renewed licence to explore oil and gas prospects in the Old Harry site in 2017.

Environmental groups including the David Suzuki Foundation and Sierra Club Canada Foundation argue the licence should not have been reissued and that the decision lacks proper environmental oversight.

The Old Harry site sits about 80 kilometres off the southwest tip of Newfoundland, near the border with Quebec.

Corridor announced in June 2018 it was suspending exploratory work on the project, saying there was no "viable path" to drilling an exploration well before its licence expired in 2021.

The Newfoundland and Labrador government, facing mounting debts, announced plans last year to rapidly expand its lucrative oil and gas industry to ease the province's economic woes.