UK Prime Minister Boris Johnson has made a last-minute attempt to talk Israel out of taking over parts of the West Bank.

Writing in an op-ed in Israeli newspaper Yedioth Ahronoth, Johnson said he was sad to learn about the “proposals to annex Palestinian territory.”

Johnson, whose great-grandfather was Jewish, reflected on his time at an Israeli kibbutz as a teenager and called himself a “life-long friend, admirer and supporter of Israel.”

However, he felt fear that Israel’s West Bank plans will “fail in their objective of securing Israel’s borders and will be contrary to Israel’s own long-term interests.”

Johnson warned that “annexation would put in jeopardy the progress that Israel has made in improving relationships with the Arab and Muslim world” and that it would violate international law.

“I profoundly hope that annexation does not go ahead. If it does, the UK will not recognise any changes to the 1967 lines, except those agreed between both parties,” he wrote.

Israeli Prime Minister Benjamin Netanyahu has long promised to extend Israeli sovereignty to parts of the West Bank; the Trump administration’s support and the coalition agreement he struck with Benny Gantz have given a strong boost to those plans.

Netanyahu has set July 1 as the date from which he would start the process to take over roughly 30 percent of the West Bank. However, Benny Gantz, the alternate prime minister who supports the idea, cast uncertainty on the timeframe when he called on Monday for a delay to deal with the coronavirus pandemic first.