Casino opponents and state representatives have locked horns during Monday’s court hearing of a petition challenging the Department of Interior’s September 2015 decision to award a disputed land to the Mashpee Wampanoag tribe.

The Associated Press reported that opponents of the $1 billion First Light Casino project accused the federal government of misconstruing the federal Indian Law in order to grant the 300 acres of casino land to the Mashpee Wampanoag tribe.

First Light Casino, a project of the Cape Cod-based tribe and its Malaysia-based partners the Genting Group, broke ground in Taunton in April, months after a group of local residents filed suit seeking to block the project.

Critics argued that the court should strike down the decision of the federal government to award the casino land to the Mashpee Wampanoag tribe, which they claimed was anchored on an “ungrammatical” reading of the federal Indian Law.