Israeli airline staff went on strike on Sunday to protest against a government proposal to finalise a deregulation plan with European carriers which they say would result in widespread layoffs.
"Implementing the Open Skies agreement in its current format will have severe ramifications, which would fatally and irreversibly harm civilian aviation in Israel," Histadrut trade union chairman Ofer Eini said in a letter addressed to Prime Minister Benjamin Netanyahu.
Netanyahu's cabinet was set to ratify the agreement during a cabinet meeting on Sunday.
"I urgently call on you to refrain from discussing and deciding upon the issue in this cabinet meeting, and to enter a process of dialogue and discussion on this essential national issue," he wrote.
Staff of El Al Airlines and charter firms Arkia and Israir halted work at 5:00 am (0200 GMT) on Sunday but did not say how long the stoppage would last.
El Al, Israel's national carrier, has since 2005 been under private ownership.
In March 2012, Israel and the European Union signed an Open Skies aviation agreement aimed at opening up and integrating their markets.
In line with the deal, European airlines would operate direct flights to Israel from anywhere in the world and Israeli carriers would also fly to airports across the EU, in a move that would reduce costs for travellers.