(Reuters) - North Carolina Republican Mark Harris said on Tuesday that he will not run in the re-do of a U.S. House of Representatives election that drew national scrutiny because of ballot fraud.

Harris attributed his decision to health concerns. He led by 905 votes in the Nov. 6 election, but state officials refused to certify him as the winner over Democrat Dan McCready. Last week they ordered a new election after finding the voting results were tainted.

The unanimous vote by North Carolina’s bipartisan elections board followed four days of evidence showing an operative for Harris’ campaign had orchestrated a ballot fraud scheme in the state’s 9th Congressional District.

Harris, a pastor who previously edged out then-incumbent Republican Congressman Robert Pittenger in a close primary, had sought for months to fend off a general election rerun. But on the final day of the hearing, he also called for a new election and acknowledged the public had lost confidence in November’s result.

In an email on Tuesday, Harris, who is recovering from an infection last month that led to sepsis and two strokes, said residents of the district deserved a candidate “at full strength during the new campaign.”

McCready plans to run again, although a new election date has not yet been set. The outcome of the country’s last unsettled 2018 congressional contest will not change the balance of power in the Democratic-controlled House of Representatives.

Months of mounting evidence of ballot fraud by the Harris campaign became an embarrassment to the Republican Party, which has accused Democrats without proof of encouraging individual voter fraud in races such as the 2016 presidential election.

During the elections board hearing, Harris’ son said he had warned his father of potential illegal activity by one of his political operatives, Leslie McCrae Dowless.

Residents of at least two counties in the district testified that Dowless and his paid workers collected incomplete absentee ballots and, in some instances, falsely signed as witnesses and filled in votes for contests left blank.

Dowless attended the hearing but declined to testify voluntarily after the board said it would deny him immunity. He has maintained his innocence, and Harris campaign officials said they did not pay Dowless to do anything illegal.

North Carolina Republican Party Chairman Robin Hayes said on Tuesday his party supported Harris’ decision. He said multiple candidates were considering the race, and “we have no doubt that a competitive nominee will emerge.”

Wayne Goodwin, North Carolina’s Democratic Party chairman, said the state investigation would dog Republicans no matter who jumps in.