Question juridique clé
Whether the federal appeal was admissible despite non-payment of the advance on costs.
Solution extraite
The appeal was inadmissible because the appellant did not pay the required advance even after an additional deadline.
Motifs extraits
Under Art. 62 LTF, failure to pay the requested advance within the extended deadline makes the appeal inadmissible. The appellant’s attempted set-off was ineffective because a private person may not offset a public-law claim of a public entity without its consent; the Federal Tribunal's cashier had not agreed.