Britain summoned Israel's ambassador Thursday to clarify what London called an "identity theft" in which the passports of six British Israelis were used by assassins.
A hit squad that killed senior Hamas official Mahmoud al-Mabhouh in a Dubai hotel room in January apparently forged travel documents bearing the names of the Britons, who all live in Israel.
A British diplomat told Haaretz that Israeli Ambassador Ron Prosor is expected merely to listen to London's position, rather than offer an Israeli response in his late morning meeting with British Foreign Office Under Secretary Peter Ricketts.
The diplomat said the British Embassy in Tel Aviv would contact those whose names were used to provide them with information on receiving new passports.
Although Jerusalem has not taken responsibility for the January 20 hit on Mabhouh, the incident seems to have spawned a serious diplomatic rift between Israel and the United Kingdom.
Israel's ambassador to the Republic of Ireland, Zion Evroni, said Wednesday that he too had received a summons from the country's Department of Foreign Affairs and would be meet Minister Michael Martin on Thursday.
In Jerusalem, Foreign Ministry officials declined to comment on the matter, but an Israeli diplomat said on condition of anonymity that the government has decided to withhold a public statement until the British message is received, and would then choose how to respond.
Israeli officials expressed concern Wednesday that the affair could seriously harm ties between Jerusalem and London. They said the British and Irish summonses could lead to similar steps on the part of France and Germany, other countries whose passports the assailants carried in Dubai.
One Israeli official said the Irish government had already contacted Britain, Germany and France to recommend they conduct a joint investigation into the incident.
British Prime Minister Gordon Brown promised Wednesday that his government would launch an inquiry into the use of the British passports in the operation, but did not cast blame over the alleged forgeries.
"The defrauding of British passports is a very serious issue," a statement from the Foreign Office released Wednesday read. "The government will continue to take all the action that is necessary to protect British nationals from identity fraud."
"The government is involved in a number of strands of ongoing activity in relation to this specific case," the statement said. It cited three specific areas of activity: offering bureaucratic assistance to the affected British citizens living in Israel, investigating the matter fully and summoning the Israeli ambassador for clarification.
"The Serious Organised Crime Agency will lead this investigation, in close cooperation with the Emirati authorities," the Foreign Office said.
Ireland's Department of Foreign Affairs released a statement indicating, "the identities of the persons recorded on the forged passports do not correspond to those recorded on the valid passports carrying the same numbers."
Emirati police said the team left Dubai several hours after the operation - some individually and others in pairs - for destinations in Europe, Asia and Africa.
At a memorial rally for Mabhouh in Gaza Wednesday, leaders of Hamas' armed wing said the group "will never rest until they reach his killers".
Hamas politburo chief Khaled Meshal addressed the rally of several thousand by video link from Damascus.
"We call on European countries to punish Israel's leaders for violating laws," he said. "Israel deserves to be placed on the terror list."