The whistleblower whose allegations about President Trump and Ukraine have sparked an impeachment inquiry "never worked for or advised a political candidate, campaign, or party," and spent their entire government career in apolitical positions, according to a statement released by the whistleblower's lawyers Wednesday night.

Why it matters: Republicans and the White House have been ramping up their attempts to discredit the whistleblower, seizing on an Aug. 26 letter from Intelligence Community Inspector General Michael Atkinson in which he disclosed the whistleblower showed "some indicia of an arguable political bias ... in favor of a rival political candidate."

CNN later reported that one example of potential bias that Atkinson was referring to was that the whistleblower is a registered Democrat. On Wednesday, Axios confirmed that Atkinson told lawmakers that the whistleblower previously had "some type of professional relationship" with one of the 2020 Democratic candidates.

However, Atkinson still concluded that the whistleblower's allegations appeared credible.

Details: The whistleblowers' attorneys, Andrew Bakaj and Mark Zaid, clarified in their Wednesday statement that during their client's tenure as a career government official, the whistleblower has "come into contact with presidential candidates from both parties in their roles as elected officials – not as candidates."

They note that the whistleblower "voluntarily provided relevant career information" to Atkinson to help validate his or her complaint, and Atkinson concluded that the complaint was both "urgent and credible."

The bottom line: "[T]he whistleblower is not the story," the attorneys argue. "To date, virtually every substantive allegation has been confirmed by other sources. For that reason the identity of the whistleblower is irrelevant."

Go deeper: July 26 whistleblower memo claims White House official was "visibly shaken" by Ukraine call