Washington CNN  — 

Former Vice President Joe Biden said on Thursday that President Donald Trump is trying to “hijack an election” by repeatedly pushing Ukrainian President Volodymyr Zelensky to investigate the former vice president and his son.

“He’d like to get foreign help to win elections,” Biden said of Trump at a private California fundraiser, according to a pool report, marking his strongest comments to date on the Ukraine scandal.

The Democratic presidential candidate asserted there hasn’t been “one shred of evidence” showing wrongdoing by his family, according to the report. “There’s nothing anybody in my family did wrong … at all.”

While at the fundraiser, the former vice president quoted an excerpt of a stunning whistleblower complaint that was released earlier on Thursday, according to the report. The complaint alleges Trump abused his official powers “to solicit interference” from Ukraine in the upcoming 2020 election, and that the White House took steps to cover it up. Trump has denied any wrongdoing.

Acting Director of National Intelligence Joseph Maguire on Thursday testified before the House Intelligence Committee about the complaint and defended the whistleblower, whose identity remains publicly unknown.

A transcript released by the White House shows Trump repeatedly pushed Zelensky to investigate Biden, Trump’s potential 2020 political rival, and his son, Hunter, during a July 25 phone call. Trump asked the Ukrainian leader to work with his personal lawyer, Rudy Giuliani, and US Attorney General William Barr on the issue, the call transcript reveals.

There is no evidence?of wrongdoing by either Joe or?Hunter Biden.

After Trump admitted to discussing Biden and his son on a phone call with the Ukrainian President, House Speaker Nancy Pelosi announced a formal impeachment inquiry into Trump. More than half the US House of Representatives have now said they support an impeachment investigation.

Biden?said Tuesday, shortly before Pelosi’s announcement, if Trump does not cooperate with Congress, he would leave lawmakers with “no choice” but to start impeachment proceedings. By making his call for Trump’s removal from office conditional, he stopped short of some of his Democratic rivals, including Massachusetts Sen. Elizabeth Warren, who are calling for the House to impeach Trump now.

CNN’s Arlette Saenz and Sarah Mucha contributed to this report.