DUBLIN, Ireland (AP) — Irish Prime Minister Brian Cowen appealed to Israel to let a private Irish ship deliver its aid cargo to Gaza — but conceded yesterday that supplies of concrete on board would pose a particular stumbling block because Israel considers it of military use.

The 1,200-tonne ship Rachel Corrie — named after an American college student crushed to death by an Israeli Army bulldozer while protesting house demolitions in the Gaza Strip in 2003 — carries wheelchairs, medical supplies and concrete.

The 43-year-old, 225-foot-long (69-metre-long) cargo ship was supposed to join the aid flotilla that Israeli commandos intercepted Monday, triggering clashes that left nine activists dead. But the Rachel Corrie was delayed by mechanical problems and is still several hundred miles (kilometres) west of Gaza along the Libyan coast.

Israeli officials stress that, regardless of what the Rachel Corrie is carrying, the ship will be diverted to an Israeli port if it challenges Israel’s naval blockade of Gaza. They have pledged to deliver Irish medical supplies to Gaza by road but won’t permit shipments of concrete, which can be used to reinforce military positions as well as rebuild Gazans’ homes and roads.

The Irish activists insist they won’t accept diversion to an Israeli or Egyptian port, because their campaign is designed to challenge the naval blockade and Israel’s right to dictate what goes into Gaza. They insist the ship contains no material that would further the war aims of Hamas.

The Irish stand has received no clear-cut support from European Union partners. They criticised Israel’s naval blockade as counterproductive, but declined to call specifically for Israel to permit the Rachel Corrie to dock at the Port of Gaza.

In London, British Prime Minister David Cameron said the three-year-old naval blockade and strict border controls on the Gaza Strip had done nothing to dislodge the militant Hamas movement from power.

“Friends of Israel — and I count myself a friend of Israel — should be saying to the Israelis that the blockade actually strengthens Hamas’ grip on the economy and on Gaza, and it’s in their own interests to lift it and allow these vital supplies to get through,” he said.

In Brussels, aides to EU foreign policy chief Catherine Ashton steered clear of any direct stance on Ireland’s appeal.

Ashton spokesman Darren Ennis said EU leaders want all crossings into Gaza “opened immediately for humanitarian aid, commercial goods and persons. Keeping Gaza closed is unsustainable.”

On board the Irish vessel is Mairead Corrigan, a 1976 Nobel Peace Prize winner from Northern Ireland whom Israel last detained and deported in July 2009 as she tried to deliver aid by sea to Gaza. Also taking part is Denis Halliday, who ran UN humanitarian aid programmes in Iraq in 1997-98 before resigning in protest at US-led economic sanctions against Iraq.

Another activist on the ship, Irish electrician Derek Graham, said all aboard had agreed to offer no resistance if their ship is boarded by Israeli soldiers. He said they expected to reach the disputed waters Friday or Saturday, and had agreed to sit down and put their hands in the air as Israeli forces approached.

Cowen told lawmakers that Ireland has formally appealed to Israel to let the ship “complete its journey unimpeded and discharge its humanitarian cargo in Gaza”, but was not optimistic this would happen.