Israel's top court on Sunday struck down a landmark deal aimed at paving the way for the exploitation of Mediterranean gas reserves, in a major defeat for Prime Minister Benjamin Netanyahu.
A panel of Supreme Court justices said in their ruling that a clause in the plan that prevented it from being changed for a decade was unacceptable.
"We have decided to cancel the gas deal because of the stability clause" that would have barred future governments from altering the deal, the justices said.
The court however suspended the ruling for a year to enable the parliament to amend the agreement.
Critics of the deal between the Israeli government and a consortium including US firm Noble Energy say it is overly favourable to the companies involved.
Netanyahu, who pushed forward the deal and even appeared at the court to defend it, used an obscure clause to override the anti-trust authorities.
That allowed it to move forward with the approval of the economy minister -- a portfolio he holds after the previous one resigned over the gas deal.
The deal, signed in December with Noble and its Israeli partner Delek, would have regulated the development of the Leviathan field in the eastern Mediterranean, one of the biggest recent natural gas discoveries, in addition to other issues.
The consortium is said to have agreed to invest $1.5 billion to develop the Leviathan field over the next two years.
Failing to meet the requirement would have allowed the government to back out of a commitment not to alter fiscal and regulatory terms for the gas industry until 2025.