By Jeremy Herb and Pamela Brown, CNN

(CNN) -- The White House is rejecting House Oversight Chairman Elijah Cummings' request to interview a former White House official who now represents the Trump Organization, the latest skirmish between the Trump administration and the House Democrats investigating President Donald Trump and his administration.

In a letter to Cummings, White House Counsel Pat Cipollone accused the committee of making "grossly unfair" allegations against Stefan Passantino and Trump's personal attorney Sheri Dillon and damaging their reputations.

Last month, Cummings sent a letter to Cipollone that stated the committee had obtained new documents showing Passantino and Dillon "may have provided false information" when they were questioned by federal ethics officials about hush money payments paid to adult-film actress Stormy Daniels.

Cummings requested an interview with both attorneys.

In response, Cipollone chided Cummings for directly requesting an interview with Passantino, instead of going through the White House counsel's office, and said the White House would not make Passantino available.

"In response to your request, given longstanding law and practice, we are not inclined to make the former Deputy Counsel to the President available for a transcribed interview inquiring into his conversations and advice he provided while serving as Deputy Counsel to the President," Cipollone wrote.

The response is likely to further exacerbate tensions between the White House and Cummings, who has expressed frustration at the White House's response on a number of issues he is investigating, including security clearances of the President's advisers.

Earlier this month, Cummings threatened to issue a subpoena if the White House didn't comply with his request on security clearances following a report that Trump had personally intervened to secure a clearance for his son-in-law Jared Kushner.

Cummings' office did not immediately response to CNN's request for comment on Cipollone's new letter on the attorneys' statements to ethics officials. Last week, Cummings said he was still determining what steps he would take in response to White House resistance to their request for information.

In his letter last month, Cummings pointed to notes his committee obtained that cited a federal Office of Government Ethics official referring to the "changing explanations and excuse from the President's legal team as 'evolving stories.'"

But Republicans and the White House have pushed back on Cummings' allegations, saying the Democrats hand-picked information from the Office of Government Ethics.

"The Committee's unfortunate failure to maintain even the semblance of proceeding in a neutral search for the facts is further evidenced by the fact that the Committee placed only 19 pages from OGE's production to the Committee on its website," Cippolone wrote. "The full production by OGE totaled 282 pages."