WASHINGTON — Lev Parnas, the Soviet-born businessman who played a central role in the campaign to pressure Ukraine to investigate political rivals of President Trump, completed his break with the White House on Wednesday, asserting for the first time in public that the president was fully aware of the efforts to dig up damaging information on his behalf. In an interview with The New York Times on the day the House transmitted articles of impeachment against Mr. Trump to the Senate, Mr. Parnas also expressed regret for having trusted Mr. Trump and Rudolph W. Giuliani, the president’s personal lawyer and the architect of the Ukraine pressure campaign. His lawyer said he was eager to cooperate with federal prosecutors investigating Mr. Giuliani. In the messages, Mr. Giuliani boasted of the effort to secure the visa: “It’s going to work I have no 1 in it.” Mr. Parnas said the reference to No. 1 was to Mr. Trump. “I am betting my whole life that Trump knew exactly everything that was going on that Rudy Giuliani was doing in Ukraine,” Mr. Parnas said. Lev Parnas, Key Player in Ukraine Affair, Completes Break With Trump and Giuliani Come on Trump Humpers and tell us how much of a liar that Lev Parnas is and that he is just making all this up to save his own skin.