The land was given to Britain and they gave it to Israel and Jordan case clkosed.
False .
In actuality they could have annexed them as part of Israel also.
False .
Israel could have kept all of Gaza and the Golan hieghts plus al of the westbank if they really wanted to. No one could stop them.
False .
The palestinians were not slaves but rented the land they lived on and had a legal contract to do so. The land belonged to Turkish landlords not the people working on the land.
False , unless you want to add a few calarifications and provide details of the lease agreement to those Palestinians who were only tennants not land owners .
There were no 'Palestinians' until Arafat named them that
False .
In fact the original Palestinians were the Jews.
False (read your bible 0
So Gawain , are you suffering from memory failure or just hoping that if you repeat lies often enough they will magically become true ?

From what i have gathered from this thread, Britain did in fact give the land to the Israelis..
Not quite Panzer , and as it has been wrongly mentioned several times in this thread on Land ownership , Britain did not own the land , it held the land as a trustee for the citizens of that land . In violation of the terms of its Mandate it gave some of the land to people who had abolutely no claim to the land (by residency or history) they were given , that became Jordan . Under the terms of the Mandate and the Balfour declaration Britain had an obligation to create a Jewish Homeland , but both the documents had clauses in them that meant it was nigh on impossible for this objective to be achieved , unless they wanted to put up with huge expense and decades (if not centuries) of bloodshed .
So they passed it to the UN the UN called for a fair and equitable settlement , after many failures to achieve this they settled on an unfair and unequitable settlement that was forced through despite all the protests .
The Jewish State was not given all of the land , it was given the majority even though its Land ownership holdings were miniscule (6-8%)and its population was the minority (and the vast majority of those were recent immigrants) .
On top of that they siezed several towns prior to Indepdence that they had not been allocated under the partition plan .
So back to your first question , do the Palestinians have any legal claim to the lands that are now Israel , yes , they also have the right to return to those lands as they are refugees who fled a conflict .
But they are not going to get their legal rights anymore than Israel is going to evict its own illegal settlers from all the occupied territories .