Israel should take every step to avoid harming civilians in an offensive against Gaza, Rishi Sunak has said, amid pressure over balancing support for the response to Hamas’s attacks with concern about a potential humanitarian catastrophe. “Of course we should always – and we are always – having concerns of civilians paramount in our minds,” Sunak told broadcasters in Gotland, Sweden, where he was attending a military summit of northern European nations. “It is something I’ve discussed with [Israeli] prime minister Netanyahu myself and underlined with what the secretary of state from the United States and the [US] president have said, that of course Israel should take every possible precaution to protect civilians as they exercise their rightful ability to defend themselves against attacks like this.” Asked whether UK support would remain “regardless of what Israel does”, Sunak replied: “It is important to remember why we are in this very difficult situation. “That is because Hamas, a proscribed terrorism organisation, committed an appalling act of barbarity and has killed over 1,000 Israelis, including women and children, in scenes that are quite frankly horrific and we haven’t seen in decades. “It is unequivocally wrong and there is no moral ambiguity about that. Israel has every right to defend itself and take the action that is necessary to ensure the protection and security of its citizens, and that nothing like this can ever happen again.” Earlier, Grant Shapps, the defence secretary, defended Israel’s order for more than 1 million people in and around Gaza City to move to the south of the territory for their safety within the next 24 hours, something the UN said was impossible “without devastating humanitarian consequences”. However, Shapps would not say whether he thought it feasible for nearly half the entire population of Gaza to move within this timescale, saying only that Israel had a right to take action after the massacre of more than 1,300 people in Israel by Hamas on Saturday. More than 1,500 Palestinians, a third of them children, have been killed in the retaliatory strikes, according to Gaza’s health ministry. Shapps told BBC Radio 4’s Today programme: “When Hamas went in the other way round, there weren’t any of these options, they went to just murder people. Now the option for Israel is either to just ignore this and allow it to happen again, or actually deal with Hamas.” He later told Sky News it was “highly likely” Britons would be among those kidnapped by Hamas. “We don’t have exact data on that for obvious reasons. But within Gaza, there will also be Brits, or possibly people with dual nationalities as well,” he added. Shapps was speaking after Sunak announced British military ships and aircraft would be deployed to the region to help with humanitarian efforts and track the movement of weapons. Charities have urged Israel to reconsider its evacuation order, with the UK aid group Oxfam calling it “both utterly inhumane and impossible”. Labour has taken a similar line, saying in general terms that Israel should abide by international law, but refusing to condemn specific action, such as cutting water and food supplies to Gaza. This has prompted some pushback, with two Oxford city councillors, Shaista Aziz and Amar Latif, resigning the Labour whip over what Aziz called the party leadership’s refusal to condemn “collective punishment” for people in Gaza. Lubaba Khalid, the black, Asian and minority ethnic officer for Young Labour, said she had resigned from the role, calling Labour “no longer a safe space for Palestinians and Muslims”.