Israeli Prime Minister Prime Minister Benjamin Netanyahu is making an unprecedented appearance at the Supreme Court to defend a deal signed in December with U.S. and Israeli developers drilling offshore gas deposits.

Israel's Channel 10 TV reported Netanyahu as telling the court Sunday that if Israel were to alter its deal investors could turn to buy gas from Israel's enemies instead.

Resource-poor Israel announced the discovery of sizeable offshore natural gas deposits about five years ago, and a partnership of Israeli and U.S. companies began extracting gas. After the country's antitrust commissioner determined the gas companies' ownership constituted a monopoly, a government committee reached a deal with the firms to introduce competition.

Opponents challenged the deal in court because they say it favors the developers over the Israeli public.