WASHINGTON (Reuters) - America First Policies, a political action group backing U.S. President Donald Trump, will launch an advertising campaign aimed at vulnerable House Democrats who support the impeachment inquiry against him, a source familiar with the plans told Reuters.

FILE PHOTO: U.S. President Donald Trump looks on during a ceremonial swearing-in for Labor Secretary Eugene Scalia at the White House in Washington, U.S., September 30, 2019. REUTERS/Leah Millis/File Photo

The television and digital ad buy, which the source said would cost more than $1 million, will encourage voters to tell their Democratic representatives in Congress to oppose the impeachment probe.

The ads are designed to echo a $2 million campaign the Republican National Committee launched over the weekend, and will be set to run when those ads are completed, likely at the end of this week or the beginning of next week, the source said on Tuesday.

Democrats in the U.S. House of Representatives launched the impeachment inquiry following a whistleblower report that accused Trump of soliciting foreign interference in the 2020 U.S. election for his personal political benefit.

Democrats are looking into Trump’s request to Ukrainian President Volodymyr Zelenskiy during a July 25 phone call to investigate former U.S. Vice President Joe Biden, a leading contender among Democrats seeking to take on Trump in next year’s election.

Trump denies wrongdoing and has assailed the inquiry.

The inquiry could lead to approval of articles of impeachment - or formal charges - against Trump in the House. That would lead to a trial in the Senate on whether to remove him from office. But the president’s fellow Republicans control that chamber and have shown little appetite for removing him.

America First Policies is a super PAC permitted to raise and spend unlimited sums of money but must disclose both fundraising and expenses. As a super PAC, the group is prohibited from directly coordinating with either the Republican National Committee or Trump’s campaign.

The ads are being run by the America First non-profit arm, which is not required to disclose how much money it raises or spends, but is prohibited from funding advertisements that directly advocate voting for or against a candidate.

The ads will point to the “kitchen-table” issues that Democrats campaigned on during the 2018 congressional elections, like healthcare and the border.

“Now you’re doing nothing, all you do is investigate, investigate, investigate,” the source said, summarizing the intended message. “It’s a call to action.”

The ads will target districts that elected Democrats in 2018 after going for Trump in the 2016 election.

“We’re going to be putting pressure on moderate Democrats,” the source said.