Despite essentially boycotting Prime Minister Binyamin Netanyahu’s speech to Congress by planning to be abroad when it takes place, U.S. Vice President Joe Biden on Saturday met with another Israeli official.

Biden and Opposition leader Yitzhak Herzog, head of the Labor party, met on the sidelines of the Munich Security Conference.

The meeting, which was described as “informal”, was part of a series of meetings that Herzog made with several leaders, including U.S. Secretary of State John Kerry, German Foreign Minister Frank-Walter Steinmeier, the European Union’s Foreign Affairs Representative Federica Mogherini, the President of the EU, and British Foreign Secretary Philip Hammond.

The meetings came just one day after an official in Washington said that Biden would be “traveling abroad during the joint session of Congress” during which Netanyahu is to speak, a reflection of the White House’s anger over the speech. The speech was initiated by House Speaker John Boehner, who invited Netanyahu without the knowledge of either the White House's or Democratic leaders in Congress.

The Likud party was incensed at the meeting between Herzog and Biden, which also came as leaders from the left, including Herzog himself, were busy attacking Netanyahu and blaming him for Biden’s boycott of the speech.

“Buji’s behavior in Munich is an irresponsible crossing of red lines,” the party said. “As the Prime Minister is trying to prevent a dangerous agreement between world powers and Iran, the leader of the Opposition chooses to weaken Israel's position in the international arena."

“The good of the country demands that disagreements between the left and the Likud be clarified in Israel,” the Likud continued, adding, "Instead Buji runs to Munich for political and personal reasons in order to discredit the Prime Minister of Israel in violation of national interest and security."

MK Miri Regev of the Likud launched her own attack of Herzog, calling him “an indefatigable subversive”, the remark used by former Prime Minister Yitzhak Rabin in his autobiography to describe Shimon Peres.

"I guess that's the genetics of the Labor party,” said Regev. “There is no country in the world in which its elected officials choose to wash their dirty laundry outside its borders. Only here, Buji is used by the international community, cooperates with them against Israel and endangers state security.”

Meanwhile, MK Shelly Yechimovich of the Labor party fired back at the criticism and said, "The meeting with Vice President Biden in Munich shows that when Herzog speaks, the world listens, and that the only bridge for normal and harmonious communication with the international arena is to elect Herzog for prime minister."

"Netanyahu boasts that when he speaks the world listens, but now it is clear that Netanyahu can speak and talk to the wall and the world turns its back on him, while he has to settle on staged conversations with the United States in campaign ads,” she continued.

"Israel, which needs international support and certainly the support of the United States, cannot afford a prime minister who endangers its security and its status for domestic political bonuses. The fact that Biden will be absent from Netanyahu's speech in Congress in such an unusual step, but found it necessary to meet Herzog, speaks for itself. Netanyahu's false patriotism is nothing but dangerous political egoism,” said Yechimovich.