The erection of a tent city to house African migrants has cost Israel some NIS 50 million, the state told the High Court of Justice yesterday.

The brief also noted that the number of migrants entering the country in June and July was smaller than in the same period last year. In June, for instance, 928 migrants entered, down from 1,321 in June 2011.

Army officers serving along the southern border also told Haaretz that the drop has been substantial: There are nights now when not a single migrant arrives, which hadn't been the case for a long time previously, they said.

But the decline could be due to temporary factors, such as "the weather, the situation in Egypt, etc.," the brief warned. "Therefore, it's premature to say whether a change in the trend can be discerned."

The tent city will initially hold about 1,000 people, and is expected to get its first residents in mid-August at the earliest. There are currently 2,300 spaces available in the existing detention facilities of Ketziot and Saharonim, and those will likely be filled first.

The brief was filed in response to a petition by Bimkom - Planners for Planning Rights against the project's exemption from certain planning regulations. Nir Shalev of Bimkom said yesterday that the combination of the drop in the number of migrants and the large number of available beds at existing facilities makes the entire project unnecessary.