BEIRUT (Reuters) - A planned visit by the head of the Maronite church to Jerusalem has stirred an outcry in Lebanon, which is still technically at war with its southern neighbor Israel.

Lebanon's Patriarch Beshara al-Rai said last week he would join Pope Francis during a May 24-26 tour of the Holy Land, a visit that would make him the first Maronite patriarch to do so since its creation in 1948.

Supporters say the trip will help affirm Jerusalem's multi-religious character, while critics have accused the church leader of legitimising a state many Arabs see as a symbol of injustice, humiliation and occupation.

"We cannot find words to describe it other than as a terrible mistake which history books will remember in deep red," read an article in the Lebanese newspaper Al Akhbar.

"It will be a 'suicidal step' it could be difficult to remedy in the future," it said.

Palestinian reactions have been divided. "Welcome to Palestine, your second home," President Mahmoud Abbas said in a message to Rai. But the Islamist movement Hamas urged the trip be cancelled, saying it would "normalise" Israel's occupation of lands Palestinians want for a future State.

Rai, a Catholic Cardinal, is the leading official in the Maronite church, which follows an Eastern rite of the Roman Catholic Church. Maronites number about 900,000 in Lebanon, around a quarter of the population, and also have a presence in Syria and Cyprus.

Church officials have hurried to insist the visit would not amount to normalisation and said Rai has been clear in his opposition to Israeli occupation of Arab lands.

Addressing the furore on his return from Europe earlier this week, Rai's voice rose as he said he could not remain idle while the pope toured his region.

"My leader, the leader of the church, is coming to the land of the patriarch ... Should I stay in my house? Do I not have a clerical duty to receive the Pope?" Rai said.

"I'm going to Jerusalem to say this is our city, and Jerusalem is Arab."

Vatican spokesman Federico Lombardi said Rai was not part of the official delegation and was going on his own initiative.

A "HISTORIC SIN"

The dramatic reactions to Rai's visit are rooted in Lebanon's conflicted history with Israel stretching back to their foundation after European colonialists withdrew from the Middle East following World War Two.

Israeli forces, whom the Lebanese army still refer to as the "enemy" in its press releases, have fought multiple wars on Lebanese soil, most recently in 2006. Border tensions sometimes flare into shelling or shooting.

Without directly criticising the patriarch, Shi'ite cleric Sheikh Ahmed Qabalan suggested the visit was not well timed given the "difficult circumstances" in the region. Al-Safir newspaper went further, calling the visit a "historic sin."

Others have accused Rai's critics of using the issue to distract from domestic political problems - Lebanon's parliament has been unable to choose a president, meaning the seat may be vacant after May 25.

Lawmaker Marwan Hamadeh suggested the attacks on Rai stemmed from his criticism of parliament's failure to elect a president, and said the visit to Jerusalem would help the church "lift the Jewish shroud Israel is trying to wrap around it."

Hezbollah avoided taking an official position on the visit.

Reactions in the Palestinian territories have reflected the divide between Hamas, the Islamist movement controlling the Gaza Strip, and the Fatah movement of Mahmoud Abbas in the West Bank.

The two factions signed a reconciliation deal to form a unity government last month but remain divided over how to resist Israeli occupation.

Hamas urged that Rai cancel his visit because it would amount to "normalization," or accepting Israel's occupation of lands Palestinians want for a future state.

"The occupation uses these kinds of visits to improve its image and seek to normalize relations with the Arab nation," Hamas spokesman Sami Abu Zuhri said.

(Reporting by Nidal Al Mughrabi in Gaza, Noah Browning and Ali Sawafta in Ramallah, Alexander Dziadosz and Laila Bassam in Beirut, Malak Ghobrial in Egypt and Philip Pullella in Rome; Writing by Alexander Dziadosz; Editing by Giles Elgood)