Labour’s shadow foreign secretary, Emily Thornberry, made a swingeing attack on the government’s Israel-Palestine policy on Wednesday, attacking the fact that the Foreign Secretary, Boris Johnson, was not present.

Instead it fell to the Middle East minister, Alistair Burt, in his renewed role at the Foreign Office, to speak on behalf of the government in a Commons debate where scores of MPs lined up to contribute.

Mr Burt’s opening remarks were repeatedly interrupted by MPs, many of whom raised issues such as the flying of Hezbollah flags in London, or violence of language. Conservative MP Andrew Percy told the House that he had been called “Israeli scum and Zionist scum” during the most recent election campaign.

The minister said it was “vital” for people on both sides of the conflict to avoid acts which undermined the prospect of peace and a two-state solution. The people of Israel, he said, “deserve to live free from terror and anti-Semitic incitement”.

However, during his speech, Burt said the government is “gravely concerned” by an increase in the pace of settlement building in the occupied West Bank. He said the move represented a “strategic threat to the peaceful resolution” of the  conflict as he urged the Israeli government to “show restraint” on settlement construction.

Burt expressed these concern amid reports this week that Israel plans to build more than 1,800 new housing units in East Jerusalem. He said: “All settlements in the United Kingdom’s view are illegal under international law.

He stressed that settlements were “far from the only problem in this conflict”, and said Israelis also deserved to “live free from the threat of terrorism and anti-Semitic incitement”.

But Ms Thornberry, in a long and measured response to Mr Burt, cited the Balfour Declaration which had been written by Arthur Balfour himself and not delegated. “Not only words matter”, she said, “but who says them matters too”.

She complained that the Conservative Party had failed completely to mention Israel and Palestine in its 2017 election manifesto — and, while calling herself a friend of Israel and Palestine, mocked Conservative supporters of Israel for raising the issue of Labour leader Jeremy Corbyn and his “Hamas and Hezbollah friends”. This, said Ms Thornberry, was a “Lynton Crosby” line, the former adviser to the Conservative leadership, who had been discredited.

She believed, she told MPs, that Britain’s failure to delineate its policy towards the peace process was because it was afraid to be at odds with what the Americans might say or do. “This government is so weak and wobbly that it has to be in lockstep with the US.” Instead, she said, Britain should be ready to condemn Donald Trump and part company with his attitude where necessary.

Ms Thornberry also asked for the government to publish its report on the funding of extremist groups, particularly asking to discover whether Qatar or Saudi Arabia had been responsible for any such funding.

Labour Friends of Israel chair Joan Ryan MP also addressed the debate, criticising settlement building, as “wrong for Palestine.. wrong for the prospects of peace.. wrong for Israel”. She echoed former US secretary of state, John Kerry however, in suggesting that although settlements are an obstacle, they aren’t “the whole or even the primary cause of this conflict”.

Ryan also accused the the Palestinian Authority incentivising terrorism “by paying salaries to those convicted of heinous crimes” and called for the establishment of an “independent, cross-party inquiry” into British aid to the PA.

She said Britain “cannot continue to write blank cheques to the PA and issue rote condemnations of incitement which are ignored time after time”.

The long-time Palestinian supporter Crispin Blunt warned that the commemoration of the 100th anniversary of the Balfour Declaration was “a touchstone issue for millions of Arabs and Muslims, and needs to be handled with utmost care.” Last year, he said, Britain had said it would neither apologise not celebrate the Balfour Declaration, an approach he welcomed and wanted to be reiterated.

In a passionate address to the House, Chipping Barnet Theresa Villiers spoke of payments made by the Palestinian leadership to terrorists and the fact that 25 Palestinian schools were named after terrorists. There would be outrage, she suggested, if such a thing were to happen in the UK.