The debate in the U.K. over how to respond to the Israel-Hamas conflict has been marked by divisions within leading political parties and mass protests putting pressure on officials to call for a ceasefire in Gaza.

The government has been a staunch backer of Israel in the conflict. Prime Minister Rishi Sunak visited Israel after the Hamas attack and said it represented ”the world’s darkest hour,” borrowing a phrase attributed to Winston Churchill during World War II. Sunak has also called for de-escalation and “humanitarian pauses” to the conflict, but has stopped short of calling for a full ceasefire. A junior member of Sunak’s government was fired this week after writing a letter to the premier urging him to support a ceasefire.

Within the main opposition Labour Party — which is far ahead in opinion polls with elections due in the next year or so — leader Keir Starmer is under pressure to call for a ceasefire. Tensions over the war risk derailing Starmer’s journey to Downing Street, Martin Ivens writes in Bloomberg Opinion. The mayors of London and Manchester, as well as the Scottish Labour leader, have all called for a ceasefire. Starmer took the helm of the party in 2020 and promised to “rip antisemitism out” of Labour’s ranks and purge members over claims of antisemitism that hung over the party. Starmer, who has backed calls for “pauses,” risks alienating a swath of his base in doubling down on his opposition to a ceasefire, Ivens argued. More than 20 local Labour councillors have quit the party in protest, and large pro-Palestine demonstrations have filled the streets of London. The divisions have also played out in the country’s media landscape, as a Jewish staffer for the left-leaning Guardian newspaper published an anonymous op-ed saying they ”don’t feel safe at work" and criticizing the paper’s coverage, arguing its coverage is unfairly anti-Israel.

The Israel-Palestine conflict is intertwined with the U.K.‘s history. Britain captured Jerusalem from the Ottoman Empire in 1917; following World War I, it was awarded a “mandate” to administer Palestine and also endorsed “a national home for the Jewish people” there. The British withdrew in 1948, the same year Israel was established, after several years of contentious rule and clashes between Jewish and Arab forces. Under the British, Reuters wrote in 2018, “the early Zionist movement was able to lay the groundwork for what would become modern Israel.”