Prime Minister Benjamin Netanyahu faced international and domestic criticism on Friday after his office announced that the Israeli military would escalate its nearly two-year-old campaign in the Gaza Strip.

Statements by Britain and the families of hostages held by militant groups in Gaza reflected Mr. Netanyahu’s intensifying clash with both some longstanding allies abroad and supporters of hostages at home.

“The Israeli Government’s decision to further escalate its offensive in Gaza is wrong, and we urge it to reconsider immediately,” Keir Starmer, the prime minister of Britain, said in a statement. “This action will do nothing to bring an end to this conflict or to help secure the release of hostages. It will only bring more bloodshed.”

In recent weeks, many European countries have urged Israel to end the war in Gaza, which has killed tens of thousands of Palestinians, reduced cities to rubble and caused a widespread hunger crisis. The Hamas-led attack on Israel on Oct. 7, 2023, which ignited the war, killed about 1,200 people and about 250 people were taken captive to Gaza.

The Hostages and Missing Families Forum, a group representing many families of hostages, said the Israeli government had issued a “death sentence to the living hostages” and ”a disappearance sentence” to the bodies of those killed in captivity.

“There has never been a government in Israel that has acted with such great determination against the national interest,” the group said in a statement. “The security cabinet chose another march of folly on the backs of the hostages, the fighters, and all of Israeli society.”