I read on a German site that Lola has asked the FIA to enter F1 in 2014 with the 13th entry, which should still be available since USF1 didn't materialize.
Apparently, Lola's Business manager Robin Brundle, Martin's brother, was adamant about returning to F1
Lola plant Formel 1-Einstieg für 2014 - Kampf um den 13. Startplatz - Formel 1 Nachrichten News Artikel - Motorsport-Magazin.com