Israel's parliament has passed a law requiring a super-majority to relinquish control over any part of Jerusalem, a move that could hamstring the city's division in any future peace deal.
The amendment bars the government from ceding Israeli sovereignty over any part of Jerusalem without approval of at least 80 of the legislature's 120 members.
But the law itself can be overturned with a simple majority, making it largely symbolic.
The legislation also permits the government to remove outlying Palestinian neighbourhoods from the city, a move promoted by hardliners to preserve Jerusalem's Jewish majority.
They would be turned into separate municipalities under Israeli control.
The Knesset approved the legislation in a 64-52 vote early on Tuesday, with opposition politicians saying it would make it even harder to make peace with the Palestinians.
Israel claims all of Jerusalem as its capital.
The Palestinians want east Jerusalem, which Israel captured in the 1967 war and annexed in a move not recognised internationally, to be the capital of their future state.
Tensions rose after President Donald Trump declared Jerusalem to be Israel's capital last month, breaking with decades of US policy and an international consensus that the city's status should be decided in peace negotiations.
Palestinian President Mahmoud Abbas called the legislation "tantamount to declaring war on the Palestinian people".
"This vote clearly indicates that the Israeli side has officially declared the end of the so-called political process and has already begun to impose dictatorial and de facto policies," Mr Abbas's office said in a statement.
The amendment came days after the ruling Likud party's central committee called for the annexation of West Bank settlements.
The steering body's decision was symbolic, but indicative of the prevailing opinion of prime minister Benjamin Netanyahu's party, which is opposed to the internationally backed concept of a two-state solution.
The Palestinians condemned that decision and accused Mr Trump of emboldening the Likud party.