Italian Justice Minister Clemente Mastella has resigned after police placed his wife under house arrest following an investigation into corruption in the local health care system. Mastella, who is also under investigation, still controls seats in the Senate.

Prime Minister Romano Prodi, who had a razor-thin one-vote majority prior to Mastella’s resignation, now faces an impending confidence vote, scheduled Thursday. Mastella has withdrawn support from Prodi’s coalition. Of course, he can still vote with Prodi, making him a kingmaker. Indeed, he hints this may be his plan:

“We will be demanding, not like before when we accepted compromises,” Mastalla said, quoted in the International Herald Tribune.

Seeing as how he is under investigation for corruption, what demands exactly would those be? As tools for pressure on a prosecuting government go, this is a pretty big lever.