Prime Minister Benjamin Netanyahu has defended his decision to push for a submarine deal with Germany amid mounting pressure from opposition lawmakers, who say the deal is tainted by conflicts of interest.

"Strengthening the security of the state of Israel was my only consideration in purchasing these submarines," Netanyahu said Sunday at the beginning of the Knesset meeting in Jerusalem.

In Israel, there have been calls for an inquiry after it was revealed the prime minister's personal attorney, David Shimron, had represented the German firm Thyssen Krupp which built the six Dolphin-class submarines.

"This is the prime minister's attorney, who is also a private attorney, and the Netanyahu family lawyer, and also a lawyer who serves as the prime minister's official representative. He has a finger in every pot. And it was Netanyahu, of all people, who did not know that Shimron was involved with the submarines?" asked Yediot Ahronot columnist Ben-Dror Yemini.

Former Defense Minister Moshe Yaalon has also sought to distance himself from the deal saying he was not privy to the negotiations over the 1.4 billion euro ($1.5 billion) deal. "I was strongly against the purchase of three additional submarines," Yaalon wrote on his official Facebook page last week. The defense minister urged an investigation into the "very disturbing" allegations.

The Israeli military currently has five German submarines, the purchase of which has been partly financed by a 30-percent discount; the fleet is expected to grow to six in 2018. A framework agreement to buy three new submarines was approved by the Israeli government on October 26.

In Germany, there have been questions about the submarines' capability to launch nuclear missiles. Israel is alleged to possess an undeclared arsenal of nuclear weapons.

jar/jm (AP, dpa)