CAIRO, June 5 (Reuters) - An Egyptian court ordered the government on Saturday to consider revoking the citizenship of Egyptians married to Israelis if the marriage posed a threat to Egypt's national security.

The High Administrative court's ruling, which had been timetabled before the outcry over Israel's lethal raid on an aid flotilla heading to Gaza, comes in response to an appeal by the Interior Ministry over an earlier lawsuit in a lower court.

The court asks the Ministry of Interior to present all the marriages to the cabinet to examine ... Each case should be investigated separately and with consideration to personal freedoms and the nation's security, Judge Mohamed al-Husseinay said.

In the earlier lawsuit, a lawyer argued that Egyptians married to Israelis were a risk to national security because they could be spying on Egypt for Israel.

Egypt maintains strong diplomatic and economic ties with Israel since signing a peace deal 30 years ago after the two countries fought four wars, but resentment lingers among some ordinary Egyptians over Israel's conflict with the Palestinians.

In February, the same court gave Egypt legal clearance to allow natural gas exports to Israel, canceling a lower court's verdict to stop exports.

A rights activist said the ruling demonstrated mixed messages about Egypt's ties with Israel.

The government is so strange. It says it is a friend of Israel... The president congratulates Israeli's president in national holidays yet it punishes the people for having relationships with Israel, Negad al-Borai, lawyer and a rights' activist said.

I am so surprised by the verdict. Egyptian law says citizenship can only be revoked if the citizen is proven to be spying on his country, and this verdict considers marrying an Israeli an act of spying. (Reporting by Yasmine Saleh; Editing by Alison Williams)