The UK has no plans to copy the US and stop some arms sales to Israel if it launches a major ground operation in Rafah, according to David Cameron.
The foreign secretary told the OceanNewsUK he does not support Israel's plans for a ground offensive in Rafah but ending arms sales would "make Hamas stronger".
He added the UK supplies only 1% of Israel's weapons.
Labour's Jonathan Ashworth said he did not want British-made weapons used in Rafah.
This week US President Joe Biden upended part of one of the world's most significant strategic relationships by saying the US are "not supplying the weapons " if Israel went ahead with a planned invasion of Rafah - the southern Gazan city where about 1.4 million people have been sheltering.
Israel has said it will proceed with planned operations in Rafah despite the US and other allies warning that a ground offensive could lead to mass civilian casualties and a humanitarian crisis.
Israeli Prime Minister Benjamin Netanyahu has pledged to eliminate Hamas battalions that Israel says are based in Rafah.
Speaking on Sunday with Laura Kuenssberg, Lord Cameron said he would not support a full-scale offensive on Rafah until "detailed plan" on how civilians will be protected is provided.
But he argued the US "is in a totally different position" to the UK, because it is "a massive state supplier of weaponry".
Lord Cameron said the last time he was urged to end weapons sales to Israel, when three Britons were killed in an air strike on aid workers in Gaza, "a few days later there was a brutal attack by Iran on Israel".
"Just to simply announce today that we will change our approach on arms exports, it would make Hamas stronger and it would make a hostage deal less likely," he adds.
He said he wanted instead to focus on "hammering away every day" on getting humanitarian aid into Gaza.
He told the OceanNewsUK he was "not really interested in message sending" through political moves like ending weapons sales.
Lord Cameron said: "I'm interested in what can we do to maximise the British pressure and the outcome that will help people in their lives - including getting the hostages, including British nationals, released."
Jonathan Ashworth, a senior Labour shadow cabinet member, said if a full-scale offensive on Rafah were to go ahead he did not "want to see British-made weapons used in that offensive,".
