FOREIGN Affairs Minister Micheal Martin will join his British counterpart today to quiz an Israeli minister on the use of fake passports by alleged assassins.
Israel's foreign affairs minister Avigdor Lieberman will have separate meetings with Mr Martin and Britain's Foreign Secretary David Miliband at an EU foreign ministers' summit in Brussels.
Both Irish and British representatives will demand to know what role Israel may have played in the faking of passports and the killing of a Hamas commander.
With four of the EU's 27 countries -- Britain, Ireland, France and Germany -- linked to the affair, officials have suggested it may be brought up for discussion at the full foreign ministers' meeting, which would represent a substantial diplomatic escalation.
Israel has so far refused to confirm or deny involvement in the killing of Palestinian Mahmoud al-Mabhouh in Dubai, and the allegations of doctored documents.
Dubai police say they believe Israeli agents carried out the assassination and have released the identities of 11 people travelling on passports from the four EU countries who they say were involved.
Five forged Irish passports linked to the hit squad were found with authentic numbers but names which did not match.
Last night the Department of Foreign Affairs discounted reports that up to seven fake Irish passports were used by the assassins.
Weekend reports claimed that at least two more fake Irish passports had been linked to the hit squad in Dubai. But a Foreign Affairs spokesman discounted the claims and said that as far as they were concerned, the number of fake passports involved remained at five.
The spokesman said the five authentic passport holders had all been offered new passports by the Department of Foreign Affairs.
Several of the people implicated through passports have denied any role or that they ever visited Dubai.
Investigators suggested that Israeli spy agency Mossad copied the passports and amended them to enable the assassins to enter the emirate under false identities.
Confirming today's meeting, Mr Martin said: "I intend to meet the Israeli foreign minister in Brussels to underline our deep concern about the fake use of passports in Dubai and to seek reassurance and clarification on this very serious issue."
Mr Martin also said he planned to discuss further the issue at his regular meeting with 26 other EU foreign ministers.
The announcement of today's meeting comes after Israel's ambassador to Ireland, Dr Zion Evrony, met senior government officials in Dublin last week and insisted he knew nothing about the killing.
The ambassador is to receive an invitation to a parliamentary committee to answer questions on the use of the passports.