British Prime Minister David Cameron will likely have to reschedule, for the second time in less than a month, his planned visit to Israel next week, as a labor dispute in the Foreign Ministry appears to make his arrival impossible. Cameron is scheduled to deliver a speech in the Knesset on March 12, in what would be his first visit to Israel since he was elected in 2010.

“I just don’t see how it’ll be possible to go ahead with the visit without the cooperation of the Foreign Ministry,” Foreign Ministry spokesman Yigal Palmor told The Times of Israel on Wednesday.

“We strongly recommend that the prime minister’s visit is pushed off until after our labor dispute is resolved,” added Yair Frommer, the head of the ministry’s Workers Union, which initiated a far-reaching strike Tuesday. Israeli diplomats have suspended all preparatory work for any visits, both by Israeli officials going abroad and foreign dignitaries coming to Israel.

The Israeli ambassador to the UK, Daniel Taub, informed Cameron’s office about the ongoing strike in Israel’s Foreign Ministry. “The embassy in London delivered a message to 10 Downing Street that we will not be able to coordinate the visit due to the labor dispute initiated by the Ministry of Foreign Affairs,” Taub told The Times of Israel.

The British embassy in Tel Aviv declined to comment.

Cameron had previously been scheduled to visit Israel in mid-February, but had to push off his plans, as he was preoccupied with coordinating relief efforts for areas in the UK affected by devastating floods.

The Israeli diplomats’ strike also threatens the planned visit of President Shimon Peres to China, which has not been officially confirmed yet but is planned for April, as well as the first trip to the Holy Land by Pope Francis, scheduled for May 24-26.

On Wednesday, one day after the Foreign Ministry’s Workers Union declared another harsh rounds of labor sanctions, Prime Minister Benjamin Netanyahu and his entourage felt the effects of the strike during their current trip to California. When Netanyahu’s plane landed at the Los Angeles airport, it was greeted only by a small number of security personnel instead of the usual formal reception.

Meanwhile, Israel’s embassy in China said it was halting work on a planned visit by Peres to Beijing, as well as many other diplomatic projects, as part of labor sanctions initiated by workers who are demanding better pay from the Finance Ministry.

The embassy said it had notified the Chinese foreign office that all work on the visit had been stopped, as well as on intended visits by Welfare Minister Meir Cohen, Environmental Protection Minister Amir Peretz and Tel Aviv Mayor Ron Huldai.

The embassy has also frozen work on planned visits to Israel by delegations of Chinese bloggers and reporters, academic exchanges between the nations, and a project aiming to translate the Talmud to Chinese. A planned speech by the Israeli ambassador to Chinese high-school students and several other diplomatic engagements were canceled.

The Workers Union, which is fighting for higher salaries and better working conditions for diplomats serving abroad, published a list of more than two dozen measures that took effect as of Tuesday. For instance, Foreign Ministry officials will no longer cooperate in organizing visits of foreign presidents, prime ministers, foreign ministers and other officials. Likewise, the diplomats will henceforth refuse to assist Israeli officials currently abroad or planning overseas trips. No diplomatic passports will be issued and “no assistance whatsoever” will be granted to Israeli officials abroad. In addition, all consular services to Israeli citizens are suspended; exceptions will only be made in cases where lives are in danger or bodies need to be returned to Israel for burials.

Furthermore, the ministry is temporarily suspending any cooperation with government institutions, specifically the Finance Ministry but also the Shin Bet and Mossad intelligence services and the IDF. No diplomatic cables are being sent by diplomats and the cadets course and distribution of pro-Israel public diplomacy materials has been put on hold. Diplomats have been instructed to cease any contact with the United Nations, including Secretary-General Ban Ki-moon and the Security Council, and other international organizations, including peacekeeping missions on Israel’s borders, such as UNIFIL and UNDOF.

Last summer, the Workers Union initiated similar labor sanctions, which were suspended at the end of July when the diplomats and the Finance Ministry agreed to approach a mediator. But the talks broke down earlier this week with no result.

Itamar Sharon contributed to this report.