The contentious Republican primary for the congressional seat held by U.S. Rep. Doug Lamborn ramped up over the weekend as his leading challenger, state Rep. Dave Williams, called his opponent a liar in a televised attack ad that also lists elements of an ongoing ethics complaint against the eight-term incumbent.

The Colorado Springs Republicans have been hurling charges at each other since before ballots for the June primary went in the mail last week, with each accusing the other of backing legislation to support Planned Parenthood and other causes their campaigns hope are anathema to GOP primary voters in the heavily Republican, El Paso County-based 5th Congressional District.

The latest salvo from Williams is airing on Fox News Channel and local network affiliates, he told Colorado Politics. He said his campaign is spending more than $30,000 on the ad campaign.

“Doug Lamborn is lying about Dave Williams because Lamborn is under investigation for ethics violations: Seeking gifts, breaking nepotism laws and letting his son live in the U.S. Capitol,” the narrator says in a menacing voice in Williams’ new 30-second TV ad.

Describing Williams as a “conservative warrior” who has “always … fought the corrupt establishment,” the ad also cites votes by Lamborn on federal legislation that Williams says provided funding for Planned Parenthood and forced soldiers to undergo training in Critical Race Theory and sensitivity to LGBTQ issues.

A spokeswoman for Lamborn’s campaign said the congressman had no comment on his opponent’s new ad.

The Williams ad is responding to radio and TV ads released earlier this month by the Lamborn campaign that declare Williams was “fired” in 2020 from a volunteer position with the Colorado Trump campaign and sponsored a 2021 bill in the legislature that would have allowed motorists facing fines generated by red light cameras to pay the money to accredited charities – including Planned Parenthood and Black Lives Matter – instead of to local police departments.

Williams, who disputes his opponent’s assertions, filed a criminal complaint last week, alleging Lamborn’s ads violate a Colorado law that prohibits making false statements in political advertising. He also demanded that stations stop airing Lamborn’s ads.

A spokesman said on Friday that Michael Allen, the Republican district attorney for the Fourth Judicial District, was reviewing information submitted by Williams’ campaign.

According to emails reviewed by Colorado Politics, managers at local TV and radio stations told Williams that federal election rules required that they air Lamborn’s ad. One station manager urged him to run for Congress if he thinks the rules should be changed.

In January, the House Committee on Ethics agreed to review allegations that Lamborn misused official resources for personal purposes after a separate congressional ethics office found “substantial reason to believe” Lamborn violated House rules and federal laws. The complaint is linked to a lawsuit filed by a former staffer.

At the time, a Lamborn spokeswoman called the allegations “false and unfounded” and said the congressman expects to be cleared by the committee.

In addition to Williams, who won top-line designation on the ballot at the the GOP’s district assembly in April, two other Republicans are seeking the GOP nomination in the June 28 primary: Navy veteran Rebecca Keltie and local business owner Andrew Heaton.

Democrats David Torres and Michael Colombe are running for their party’s nomination in the district.

Ballots are due back to county clerks by 7 p.m. June 28.