Palestinian president Mahmud Abbas's visit to Beirut on Monday casts the spotlight on the plight of nearly 300,000 Palestinians in Lebanon who fear they are doomed to be refugees for life.

His brief trip comes amid renewed efforts to revive the Middle East peace process and concern in Lebanon's political circles that any deal struck on the refugee issue would be at the expense of the Lebanese.

"A permanent settlement of the Palestinians in Lebanon is a real demographic, political and security threat," Farid al-Khazen, a Lebanese MP and political science professor at the American University of Beirut, told AFP.

"Yet there is pressure toward such a solution which, if implemented, would lead to war and the destruction of Lebanon," he added.

The majority of the refugees arrived in Lebanon following the creation of Israel in 1948. A second wave arrived in the 1970s after Jordan's then king Hussein kicked out the Palestine Liberation Organisation and thousands of its fighters.

The UN Relief and Works Agency for Palestine refugees (UNRWA) lists nearly 400,000 refugees in Lebanon.

But Lebanese and Palestinian officials say the number actually resident in Lebanon may be as low as 250,000 as UNRWA does not strike off its figures Palestinians who move to other countries.

The refugees that remain live in dire conditions in 12 camps across the country of four million inhabitants.

They rely heavily on UNRWA for educational, health and other assistance because under Lebanese law they are banned from practising most professions or from owning property.

While their presence in Lebanon was supposed to be short-lived, their chance of ever returning to their homeland has dimmed with every failed attempt to settle the Israeli-Palestinian conflict.

And the glimmer of hope raised following US President Barack Obama's bid to reinvigorate the peace process has been replaced by more bitterness and cynicism as each side digs in its heels.

"The slow pace and erratic progress of the negotiations means that final status, including the refugee issue, are in effect indefinitely postponed," UNRWA commissioner Karen Abu Zayd told AFP during a recent visit to Beirut.

"I'm very concerned of the lack of attention for the refugees in the peace process."

For the Lebanese, any mention of permanently settling the Palestinians in the tiny Mediterranean country prompts an outcry and warnings that this would upset the country's confessional balance and further exacerbate political divisions.

Fresh in the minds of many is the key role the Palestinians played in Lebanon's 1975-1990 civil war, Israel's 1982 assault on Beirut and, more recently, the deadly 2007 battle at a Palestinian refugee camp in northern Lebanon between an Al-Qaeda-inspired group and the Lebanese army.

But specialists and human rights groups warn that unless the refugee issue is addressed, the camps, already considered breeding grounds for extremism, could one day explode.

"The situation in the camps is beyond what is humanly acceptable," said Khalil Mekkawi, former head of the Lebanese Palestinian Dialogue Committee that was set up in 2005 to improve living conditions for the refugees.

"There is no hope whatsoever for people living in such misery."

Mekkawi said that although UNRWA requested 50 million dollars in 2006 to improve conditions in the camps, donors had responded with only 16 million dollars which represent "a drop in the ocean".

Souheil El-Natour, a Palestinian analyst and member of the leftist Democratic Front for the Liberation of Palestine, said the refugee issue had fallen victim to Lebanon's sectarian divisions.

"The question of permanent settlement is being used as a scare tactic in Lebanese politics and this is denying the refugees their civil rights," Natour said.

Analysts warn that denying Palestinians basic rights and putting the camps off-limits to the Lebanese army allow extremist groups and outlaws to gain a foothold.

"The extremism is in large part because of the lack of a solution," Abu Zayd said. "These people are people without hope, who can't see what the future holds.

"Their plight is not only the responsibility of the Lebanese government, it's an international responsibility."