JERUSALEM (Reuters) - Israeli diplomats launched an unprecedented strike on Sunday, forcing the complete closure of embassies around the world as they escalated a dispute over pay, officials said.

The industrial action has already threatened to postpone a visit by Pope Francis to Israel planned for May - one of 25 trips by foreign officials affected by a work slowdown the diplomats began on March 5 when wage talks broke down.

By escalating the action to a full strike - the first by the diplomatic corps since the country’s establishment in 1948 - the diplomats will close all of Israel’s 102 missions abroad, paralyzing most diplomatic work with other countries and the United Nations.

“We are completely shutting down the (foreign ministry) office and missions abroad. This is the first time ever,” ministry spokesman Yigal Palmor said.

Another ministry official told Reuters: “As of now, the foreign ministry doesn’t exist. It’s not possible even to submit complaints”.

Foreign Minister Avigdor Lieberman Called the strike “irresponsible” and “a wretched decision and a display of a loss of control on union’s part.”

“We shall do whatever possible to minimize the damage to the country and its citizens,” Lieberman said.

Diplomats said the strike - involving some 1,200 foreign service employees - was open-ended and had been called after the Treasury had failed to present any acceptable proposals.

They are demanding an increase in monthly salaries, which they put at 6,000-9,000 shekels ($1,700-$2,600), and want compensation for spouses forced to quit jobs due to foreign postings. They say about a third of their number has quit in the past 15 years due to poor wages.

Yacov Livne, spokesman for the diplomats’ union, said: “the Treasury is determined to destroy the foreign ministry and Israeli diplomacy.”