Fresh headlines Wednesday say the United Kingdom is mulling restricting arms sales to Israel if it goes ahead with its planned major offensive on the southern Gaza city of Rafah, which is packed with over a million Palestinian refugees who've been forcibly relocated from other parts of the Strip.

"Further escalation of Israel’s military action in Gaza without more effort to protect civilians could put it in breach of international humanitarian law, depending on how it conducts the operation, UK officials said, speaking on condition of anonymity about internal assessments," Bloomberg reports.

Not only has London's High Court recently dealt with petitions from legal advocacy groups alleging British arms sent to Israel are being used to commit war crimes (petitions which thus far have been rejected), but the UK Foreign Secretary David Cameron has just issued a letter to Netanyahu's office calling for Israel to "stop and think seriously about the repercussions of a military offensive" on Rafah.

Earlier this week Israeli defense officials for the first time said that the offensive would likely be launched by Ramadan, which begins on March 10 this year. The military has said Hamas can avoid this by releasing all of the hostages. At the UN Security Council, the UK abstained from a Tuesday vote on a resolution calling for immediate humanitarian ceasefire. It failed due to veto from the United States.

The UK Foreign Secretary's letter said further, "we do not underestimate the devastating humanitarian impacts that a full ground offensive, if enacted, would have in these circumstances."

Israel has vowed to allow Palestinian civilians to leave Rafah ahead of the ground offensive; however, there's the practical matter of where they would go from there. A massive fence separates Gaza from Egypt, and the Egyptians have erected a large walled-in refugee camp while anticipating that many civilians will flee into the Sinai desert regardless. But Egyptian authorities have said the camp can handle only up to 100,000 people.

The Foreign Secretary's office wrote that "we continue to urge Israel to ensure that it limits its operations to military targets and take all possible steps to avoid harming civilians and destroying homes." Importantly that's when the letter emphasized that in the case of a military assault on Rafah "it is difficult to see how this could be achieved."

This official and rare warning to Israel does indeed strongly suggest that the UK's next step could be to block or at least place restrictions on arms sales to Israel. The White House has also been pressured to place 'conditions' on US arms, but has refused thus far.

This is a movement that is growing, which Tel Aviv has condemned. Al Jazeera has listed a summary of the following countries which have banned or restricted weapons transfers to Israel:

This list will likely grow if Israel does proceed with a full-on military operation in Rafah, which has already been scene of frequent air strikes and some limited ground incursions related to hostage rescue efforts. But the reality remains that the most London is likely to do is merely restrict 'some' arms to Israel.