Ismail Atallah could not hide his disgust. With both hands he squeezed an imaginary throat in front of him.

“This is what they are trying to do,” he said. “They want to strangle us. The blood of 1.5 million people means nothing to the Egyptians.”

Mr Atallah, 45, an unemployed labourer, was condemning a steel wall that Egypt is constructing on its side of the Rafah border to Gaza. The construction will see a wall some 40 centimetres thick and 25 metres deep erected across the entire 10 kilometre border of Gaza and Egypt in an effort to block the hundreds of smuggling tunnels that run under it.

The construction has prompted angry protests from Gazans. After the outbreak of the second intifada in 2000, Israel progressively constricted the flow of goods to and from the Gaza Strip. After Hamas won parliamentary elections in 2006, those restrictions grew into a full-fledged blockade. Today, the estimated 560 smuggling tunnels under the border constitute a lifeline for Gaza’s 1.5 million people, who rely on them for everything from paper towels to petrol.

Surrounded on three sides by Israel, the border in the south to Egypt is the only access Gazans now have to the rest of the world.

The Rafah crossing is, however, as per the Oslo agreements, only a transit point for travellers (and then only for a few days a month) and not a commercial crossing. Smuggling is the only way for Gazans to survive.

Egypt has justified its decision to build the wall by invoking its sovereignty over the area and insisting that the border cannot remain lawless. However Egyptian officials are aware of the potentially enormous political cost the construction could bring in terms of Cairo’s standing in a region that remains appalled at Israel’s treatment of Gaza.

Hamas spokespeople have already accused Cairo of being complicit with the Israeli siege, a charge that has been repeated by commentators from across the Arab world. Cairo did receive public support from Mahmoud Abbas, the Palestinian Authority president, PLO leader and head of Fatah, Hamas’s domestic political rival, in a statement that did not endear Mr Abbas to Gazans. Many of them consider him “a stooge of Israel”, in the words of one local journalist.

Cairo will also be wary of provoking the kind of backlash that the last attempt to seal the Rafah border provoked when, in January 2008, Hamas activists bulldozed their way through a previous border wall, a relic from Israel’s time in charge of the crossing, and hundreds of thousands of Gazans streamed over the border. Egypt, with the help of Hamas, eventually resealed the border, but the bargain seemed to include, if not explicitly, a hands-off approach to the smuggling.

The construction of the wall has already stirred a direct reaction. On two separate occasions in recent days shots were fired from Gaza at Egyptian labourers working on the wall. No one was hurt on either occasion, but there is little doubt that the shootings were meant as a clear message from Hamas, or armed groups affiliated with the Islamist movement, that Egypt was overstepping its bounds.

Egypt has recently reinforced the number of troops deployed at the border, but Cairo will be keen to avoid any direct confrontation with Hamas. Indeed, said Abu Murrad, a senior Rafah leader in Hamas’s military wing, the Izzedine al Qassam brigades, the Egyptians know as well as the Palestinians that the wall will not stop the smuggling.

Abu Murrad, a nom de guerre, said tunnel diggers had already blasted holes in the new wall and that others were preparing to dig under it. Egyptian intelligence, he said, was aware of this.

“Cairo only wants to show Washington that it’s doing something. Washington wants to appease the pro-Israel lobby that it is pressuring Cairo. Everyone wants to serve their masters.”

Moreover, Abu Murrad said, the smuggling industry is simply too lucrative for Egypt to want to shut it down. He estimated that millions of dollars travelled across the border daily as a result of the smuggling that, whether the border was under Egyptian or Israeli control, “never stopped, never will … The only way to stop the smuggling is to open the borders.”

At the border itself, it was business as usual on Sunday night. Ghazi Khalil, 26, was taking a rest after sending off a shipment of chocolate biscuits just arrived through one tunnel on a lorry bound for Gaza City.

“The wall won’t affect us,” he said in between sips of tea.

“We will either go through it or under it. We are already digging tunnels 30 metres deep.”

Gazans do fear the consequences of the Egyptian wall, whatever the “professionals” may say. Some have been stocking up on canned goods and fuel. The prospect of being even more isolated is a frightening one for Gazans, Abu Murrad acknowledged.

Nevertheless, should, against the odds, Egypt succeed in sealing the border, there could only be one conclusion, the local commander said.

“Put yourself in my shoes? What would you do? The wall,” he said, making a gesture with both arms, “would be blown to pieces.”