Democratic presidential hopeful Joe Biden unveiled a sweeping ethic plan Monday, banning lobbying by foreign governments, creating a federal corruption wathchdog agency and suggesting a constitutional amendment to end private funding of federal elections if he’s elected president.

The former vice president said the plan would “ensure no future president can ever again abuse the office for personal gain.”

Biden, one of the leading contenders for the 2020 Democratic presidential nomination, unveiled the proposals following last week’s arrest of two associates of Trump personal attorney Rudy Giuliani for allegedly funneling Russian money to federal candidates and reports the former New York mayor is under investigation by the U.S. attorney’s office he once led for violations of foreign lobbying laws.

The U.S. House has launched an impeachment investigation against President Trump for the administration’s handling of a whistleblower’s complaint involving a July 25 phone call Trump made to Ukraine President Volodymyr Zelensky in which he asked Zelensky to investigate Biden. Just days earlier, Trump had frozen military aid to Ukraine.

Biden described the Trump White House as “the most corrupt administration in modern history.” Last week, he endorsed the impeachment inquiry, saying Trump “has violated his oath of office, betrayed this nation and committed impeachable acts.”

Open Secrets reports foreign interests have spent more than $1.2 billion since 2017 lobbying the U.S. government – and that’s just the amount spent by foreign agents who filed required semi-annual reports with the Justice Department under the Foreign Agents Registration Act.

South Korea has spent the most, more than $100 million, followed by Saudi Arabia, which spent more than $59 million. Other high-spending countries included China ($43 million), Russia ($42 million), Canada (nearly $36 million) and Germany ($26 million).

"We must elect leaders with integrity, for whom the public interest is paramount. But that’s not enough. We also must strengthen our laws to ensure that no future president can ever again use the office for personal gain," the plan reads.

On Sunday, Biden’s son, Hunter, said he would resign from a private equity fund backed by state-owned entities backed by China, and the elder Biden said if he is elected president, no member of his family would work for any foreign company.

“Under a Biden administration, Hunter will readily comply with any and all guidelines or standards a President Biden may issue to address purported conflicts of interest, or the appearance of such conflicts, including any restrictions related to overseas business interests,” Hunter Biden’s attorney said in a statement. “He will continue to keep his father personally uninvolved in his business.”