In a letter sent to the government on Monday, 137 Labour members of parliament called for concrete measures against Israeli settlements, arguing that continued expansion and settler violence required a stronger response from Britain.

“There is an urgent need for accountability and concrete consequences in response to Israel’s violations against Palestinians in the occupied West Bank and East Jerusalem,” the lawmakers wrote, describing a ban on settlement trade as a necessary next step.

The signatories represent more than a third of Labour’s 402 lawmakers in the 650-seat House of Commons, highlighting growing unease within the governing party over Britain’s policy toward Israel.

The intervention presents a challenge for Prime Minister Keir Starmer, who has sought to balance Britain’s longstanding alliance with Israel and the United States against mounting domestic pressure to take firmer action over Israeli conduct in Palestinian territories.

The occupied West Bank has seen accelerated settlement expansion under Israel’s current coalition government, with several ministers advocating annexation of parts of the territory. Most countries regard Israeli settlements in the West Bank as illegal under international law, a position Israel disputes.

Violence involving Israeli settlers and Palestinian communities has also increased since the outbreak of the Gaza war in October 2023.

Responding to the letter, a spokesperson for Britain’s Foreign Office did not directly address the demand for a trade ban but said the government had repeatedly condemned settler violence and the expansion of illegal settlements.

The spokesperson said Britain continued to call on Israeli authorities to prevent attacks by settler groups and address the destruction of Palestinian property.

Britain has already adopted a series of measures under Starmer’s government, including suspending some arms export licenses to Israel, pausing negotiations on a free trade agreement and imposing sanctions on Israeli ministers Itamar Ben-Gvir and Bezalel Smotrich.

London also joined several Western allies, including France and Canada, in recognizing a Palestinian state last year.

The debate has increasingly focused on the proposed E1 settlement project, a development east of Jerusalem that critics say would divide the West Bank and undermine prospects for a contiguous Palestinian state.

Britain has publicly opposed the E1 project and, together with international partners, urged businesses not to participate in construction tenders linked to the development.

The Guardian reported that the government is considering additional measures to discourage corporate involvement in the project, although officials declined to comment on potential future sanctions or restrictions.