French organisers of the "fly-in" of hundreds of pro-Palestinian activists expected in Israel's Ben Gurion airport this weekend said Wednesday they still plan to travel despite Israeli opposition.

"We are obliged to transit through Tel Aviv (Ben Gurion) to get to the West Bank. This is not a choice," said organiser Olivia Zemor, adding that buses have been reserved to ferry the activists to Bethlehem.

Israeli security forces said Tuesday they had begun preparations for the "fly-in", and local radio reported that those who arrive are expected to be arrested by police deployed at the airport.

The French foreign ministry has advised the 500 to 600 French nationals believed to be signed up for the "fly-in" not to travel "because of the risks of expulsion or detention".

Zemor condemned the French government's position on the event, which is expected to draw a total of up to 2,000 people, primarily from Western Europe.

The campaign's organisers in the West Bank say they want to publicise Israel's control of movement into and out of the Palestinian territory and to boost solidarity with the Palestinian people.

The so-called "Welcome to Palestine" campaign, which has been dubbed a "flytilla," is taking place for the third year.

In 2010, organisers said around 100 activists were able to arrive without incident and travel to the West Bank, access to which is controlled by Israel.

But last year, Israel worked with airlines to prevent hundreds of activists from boarding planes bound for Ben Gurion, and detained and later deported others who managed to arrive.

Israel has reportedly already contacted various airlines to request that they block activists from boarding flights.