The Finance Ministry issued a strong condemnation of the open-ended strike by Foreign Ministry workers on Sunday, and appealed to employees to return to the negotiating table to reach an agreement for salary increases.

The Foreign Ministry’s Worker’s Union shut down the ministry’s headquarters in Jerusalem and all Israeli embassies and consulates across the world on Sunday.

“The Foreign Ministry Worker’s Union is holding Israeli citizens hostage, and is harming the vital interests of the state,” the Finance Ministry wrote in a statement.

The Finance Ministry had suggested a number of solutions, but the Worker’s Union refused the various offers and repeatedly insisted on larger salaries for its senior officials, according to the statement.

“We will remind you that the Foreign Ministry employees received a 20% salary increase only two years ago. The Worker’s Union refused to accept the solution and unilaterally abandoned the mediation process, headed by Judge Steve Adler. We urge the union to stop the aggressive measures and return to the mediation proceedings,” it read.

In an dramatic statement headlined “The State of Israel’s first line of defense is falling apart,” the Foreign Ministry union declared on Sunday: “The workers entirely locked the Foreign Ministry and Israeli embassies in the world, for the first time in Israel’s history.”

The move follows weeks of lower-level labor actions which have stymied diplomatic efforts abroad and stopped possible visitors to Israel from getting visas, among other sanctions.

Under the full strike, nobody will be allowed into the Foreign Ministry building, “including the political leadership and the ministry’s management,” according to the union statement.

The announcement escalates a months-old labor dispute between the union and the Finance Ministry, which could seriously disrupt Israel’s foreign policy apparatus.

Earlier this month, the Workers Union, which is fighting for higher salaries and better working conditions for diplomats serving abroad, declared a renewed round of labor sanctions, which have already led to series of cancellations of visits to Israel by foreign dignitaries and trips abroad by Israeli leaders.

All activities at Israel’s 103 embassies across the globe have been suspended until further notice, the statement read.

“The Finance Ministry has declared all-out war on the foreign service of the State of Israel and dedicated diplomats fighting for Israel’s future of Israelis every day and every hour,” said Yair Frommer, the head of the Workers Union. “We will not accept the intolerable lawlessness of Finance Ministry officials sabotaging Israel’s vital interests.”