David Cameron and Ed Miliband launched into a bitter public row over the situation in Gaza last night, even as Israel continued its offensive into the territory.
The Labour leader accused the Prime Minister of a failure of leadership on Israel's Gaza onslaught and rebuked him for his "silence on the killing of innocent Palestinian civilians caused by Israel's military action".
But his stinging accusations brought an immediate response from No 10. A spokesman said they were "shocked" that Mr Miliband would "play politics with such a serious issue". A spokesman added: "The PM has been clear that both sides in the Gaza conflict need to observe a ceasefire."
Mr Miliband yesterday urged the international community to press for a new ceasefire agreement. "With the breakdown of Friday's ceasefire and the prospects of peace seemingly distant, it is now more important than ever that the international community acts to get the two sides to agree to a renewed ceasefire, and thereafter to re-establish meaningful negotiations to achieve a two-state solution," he said.
"David Cameron should be playing a leading role in these efforts to secure peace. He is right to say that Hamas is an appalling, terrorist organisation. Its wholly unjustified rocket attacks on Israeli citizens, as well as the building of tunnels for terrorist purposes, show the organisation's murderous intent and practice towards Israel and its citizens.
"But the Prime Minister is wrong not to have opposed Israel's incursion into Gaza. And his silence on the killing of hundreds of innocent Palestinian civilians caused by Israel's military action will be inexplicable to people across Britain and internationally," he said.
Describing himself as a "supporter of Israel" and affirming Israel's right to self-defence, he then sharply criticised its campaign in Gaza. "Its military actions in the past two weeks have been wrong and unjustifiable. The escalation of violence engulfing Gaza has led, and is leading, to suffering and destruction on an appalling scale, and is losing Israel friends in the international community day by day.
"Israel's present military action will increase the future threats to its security rather than countering them. Israelis rightly and justifiably want that security, yet their government's present actions instead risk simply growing a new generation bent on revenge."
Israeli security, he insisted, "cannot be achieved simply by permanent blockade, aerial bombardment and periodic ground incursion. Instead, it requires acknowledging the legitimate claims of Palestinians to statehood, and sustained efforts to secure a viable Palestine alongside a secure Israel.
"The Government's job now is to develop a collective response, not a differentiated one, and to speak with one voice. We need the clear and unequivocal message that has not so far been provided to be sent from Britain to both sides in this conflict.
"First, the Government as a whole should condemn the escalating violence now being perpetrated by both sides in this conflict, not just by Hamas. Second, it should actively engage with other EU leaders to achieve a united European position and apply coordinated pressure on both Israel and Hamas to commit to an enduring ceasefire."
Lastly, he insisted the UK should work to ensure Europe "engages actively with John Kerry and the Arab League to re-establish a meaningful peace process" once an enduring ceasefire was achieved.
Senior members of Mr Miliband's frontbench team were quick to praise his tough stance. The shadow Work and Pensions Secretary, Rachel Reeves, said it was an "important statement" and that the "international community must do more to stop the violence". Angela Eagle, the shadow Leader of the House of Commons, said she "strongly" agreed with Mr Miliband.
But senior Tories also attacked Mr Miliband. Sir Richard Ottaway, the Conservative chairman of the Foreign Affairs Select Committee, said: "As the man who undermined the Government over Syria, [Mr Miliband] is in no position to make such comments."
Julian Brazier, a Tory junior defence minister, pointed out that the UK is one of the three biggest aid providers to Gaza and said: "It's like so much of what Ed Miliband says: he makes a bold statement and you wait and wait for... a detailed proposal. But you still wait and wait. There are no really thought-out measures."
Earlier, the former Liberal Democrat leader Lord Ashdown branded Israel's attacks on Gaza as "disproportionate" and "foolish". Speaking on BBC Radio 4, he said: "Israel makes the excuse that, because weapons are being fired from civilian areas, it's entitled to use indiscriminate total force against civilian areas. No, you're not."
The news emerged as Mr Clegg came under pressure from Lib Dem peers to withdraw the party whip from MP David Ward, who they condemn for "frequently irresponsible remarks" on the Gaza-Israel crisis.
Mr Ward angered many of his colleagues last month when he tweeted that he "probably" would fire rockets on Israel if he lived in Gaza. The Bradford East MP offered a qualified apology, but reignited the row last Friday when he tweeted: "#Hamas – you have a prisoner of war – the world is watching you – behave better than #Israel would".
The row is escalating as conflicting views over the situation within and between the three main political parties harden.
Lord Palmer, the vice-president of Liberal Democrat Friends of Israel, said that Mr Ward was a "serial offender". Lord Palmer said: "I believe his words are unacceptable. He was suspended the last time. I think he should be suspended again."
Lord Alex Carlile, the son of Polish Jewish immigrants, said he "agreed with Lord Palmer, to the extent that this needs to be resolved", while a Liberal Democrat peer claimed that Mr Ward was "an unfit person to represent the party".
Mr Ward, who has tried to make clear that he condemns violence "on both sides", said this weekend: "I'm not sure what they're accusing me of. They just do not understand the strength of feeling on this. Those who are supporters of Israel will always seek to misinterpret what I say. I don't think that you can read what I said as being anti-Semitic."
Mr Ward said he was aware complaints had been made to Liberal Democrat chief whip, Don Foster.
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies