Foreign secretary David Miliband continued to urge restraint this morning after opposing the Israeli response to Palestinian rocket attacks yesterday.
A joint statement from Mr Miliband and international development secretary Douglas Alexander came out against Israel's decision to close all crossings into the Gaza Strip.
The pair described reports of power shortages caused by the blockade as "particularly alarming" and warned of "immediate humanitarian consequences" caused by continued fuel shortages.
It also condemned rocket and sniper attacks from Gaza on Israeli border towns as "unacceptable".
Israel appeared to heed pressure from the UK and other international players including the EU, UN and US by easing the lockdown this morning.
Two trucks carrying cooking gas and three with diesel for generators passed through to allow Gaza's only power plant to operate for around a week.
As the decision was made Mr Miliband was meeting with Palestinian prime minister Salam Fayyad in London.
Mr Fayyad's Palestinian Authority only governs those living in the West Bank, as militant group Hamas controls Gaza. Its support for rocket-fire into Israel has precipitated the present crisis.
Israeli-Palestinian talks on the creation of a separate Palestinian state are becoming increasingly threatened by the ongoing violence in Gaza, but Mr Miliband reiterated hopes progress could be made in the future.
"Progress in the Middle East towards a just and stable two-state solution requires courageous leadership. That is precisely what prime minister Fayyad is able to provide," he told reporters this morning.
Liberal Democrat international development spokesperson Michael Moore said he had written to Mr Alexander calling for an urgent response to the situation in Gaza.
"Rocket fire on Israel must be condemned, but once again Israel's response affects the innocent and risks jeopardising any hopes of reaching a comprehensive peace settlement," Mr Moore commented.
"The international community's approach to this crisis has clearly failed, and if the situation is not to deteriorate beyond any hope of reconciliation it is time for the EU to step out of the shadows of US-led policy."