RICHMOND, Va. (AP) -- Conservative U.S. Rep. Bob Good, R-Va., is asking for "patience from the people of the 5th District over the coming weeks" as he hopes the final ballot count from Tuesday's primary will allow him to fend off a challenger endorsed by former president Donald Trump.

Good, who chairs the hard-right House Freedom Caucus, currently trails state Sen. John McGuire by a little over 300 votes as elections officials finalize their vote counts and mail-in ballots continue to trickle in.

The Associated Press has not yet called the race for either candidate.

If Good loses, he would be the first House incumbent to lose a primary challenge this year, with the exception of one race in which two incumbents faced off due to redistricting.

As one of the most conservative congressmen in the country, Good might be impervious to a primary challenge under normal circumstances. But he earned Trump's wrath when he endorsed Florida Gov. Ron DeSantis for president. He switched back to Trump after DeSantis dropped out, but Trump endorsed McGuire and called Good a backstabber.

McGuire's lead of roughly 300 votes translates to a margin of about half a percentage point out of more than 62,000 ballots cast.

Once the results are certified, Virginia law allows for a recount if the margin of victory is less than a percentage point. If it's within half a percentage point, the recount can be conducted at the state's expense.

In a social media post Wednesday, Good said the race remains too close to call.

"Provisional ballots and mail-in ballots are also still to be counted. We are asking for full transparency from the officials involved," he said.

Both Good and McGuire are among Republicans who have raised concerns about election integrity in the wake of Trump's false claims of voter fraud in his 2020 reelection defeat. Good was among more than 100 GOP House members who voted in January 2021 to object to the Electoral College count from states that Trump disputed.

In a pre-election telephone rally with Trump on Monday, McGuire urged supporters to deliver him a margin of victory "too big to rig."