After all the 'Russian rescue deal' talk, the news about Sauber is now back into a backwards slide. A week ago, amid reports Russian entities have saved the Swiss team with promised millions, boss Monisha Kaltenborn admitted there was a delay.
That holdup could now run Sauber off the road, with Die Welt newspaper saying Ferrari has threatened to cut off the supply of customer engines unless part of an unpaid bill is paid imminently.
And the latest news is that, with F1 tyre supplier Pirelli also not paid in 2013, "The time bomb is ticking", according to Bild correspondents Helmut Uhl and Frank Schneider.
The newspaper claimed on Sunday that the entire Russian deal could now collapse, due to the uncertain job prospects of Oleg Sirotkin.
Sirotkin, who heads up Russia's National Institute of Aviation Technologies (NIAT), is vital to the deal, with his 17-year-old son Sergey also scheduled to make his Sauber debut in 2014.
Bild newspaper reported on Monday that Sauber's worsening situation has taken yet another "dramatic" turn, with potential "insolvency" now looming.
"The Russian sponsor rescue could fail," the latest media report read.
"According to our information, the NIAT board has voted by large majority against the EUR 400 million investment," added Bild. (GMM)