Israel has continued its fourth day of air strikes on Gaza
The EU must keep up the pressure for a ceasefire in Gaza, UK Foreign Secretary David Miliband has said ahead of a meeting with his European counterparts.
He told the BBC that the EU should also urge "decent" humanitarian standards to be restored in Gaza, after four days of Israeli air strikes.
The EU and UN have called for an end to the violence. The US has said the onus is on Hamas to commit to a truce.
More than 360 Palestinians and four Israelis have died in rocket fire.
Israel says it is ready for "long weeks of action" as it continues air strikes on Gaza to try to stamp out militant rocket attacks.
Liberal Democrat leader Nick Clegg told the BBC the action went "well beyond an act of self defence from Israel" and was "intolerable in terms of its human cost".
He said: "We have to take action, not just issue words ourselves now.
"The EU foreign ministers have the chance to do that tonight in Paris. The European Union has immense leverage. It's the largest trading partner of Israel, the largest donor of aid to the Palestinian communities."
He said EU ministers should immediately suspend a proposed cooperation deal with Israel as a sign of "very strong condemnation of the sheer scale of the Israeli military response".
Mr Miliband dismissed that idea as "naive" but said EU ministers should "maintain the international calls for a ceasefire" on both sides.
"These are louder and louder calls and they are increasingly unanimous," he said.
The need for humanitarian aid was "huge", he added: "Not just for food and medicine, but also for fuel. I think there is a very important role for the EU, not just as a funder but also as a spokesman for decent standards."
Israeli PM Ehud Olmert has said the air strikes, now in their fourth day, were the "first of several stages" of military action.
Israel's defence minister Ehud Barak has promised a "war to the bitter end" to defeat Hamas, the militant group which controls the Gaza Strip.
The strikes began days after a six-month ceasefire deal between Israel and Hamas expired. Israel says it is defending its citizens from rocket attacks by Hamas.
Mr Miliband told BBC Radio 4's World at One programme: "Of course, Israel is a democratic country and Hamas is a terrorist organisation but this is about how we secure the security of Israel as well as justice for the Palestinian people.
"I believe you can defeat Hamas but you have to defeat them politically and the way to defeat them politically is to deliver on the two-state solution that, in the end, is the only hope for the Middle East."