The letter, obtained by The Hill, states, "These demands go well beyond good-faith due diligence and appear designed to be logistically and financially impossible to comply with."
McClintock challenged the IRS to show the lawfulness of the requests and forgo any further "excessive information demands."
"We request that you provide a response demonstrating how these recent requests by the IRS are consistent with precedent and supported by law," the letter said. "We further request that the IRS refrain from any additional unwarranted and excessive information demands and other dilatory tactics."
McClintock called out the Obama administration during a speech on the House floor last week, accusing it of using the IRS to quiet opposing political viewpoints.
"This administration is very clearly, very pointedly and very deliberately attempting to intimidate, harass and threaten civic-minded groups with which they disagree, using one of the most feared and powerful agencies in the United States government to do so," said McClintock.
The House Republicans who signed the letter echoed that sentiment, claiming the recent IRS inquiries were made for no reason other than the groups' political affiliation.
"Such practices chill these groups’ constitutionally guaranteed rights to civic participation, freedom of association and free speech and are better left to despotic regimes than a revenue-collection agency in a free country," they stated.
A spokesman from the IRS said in a statement, "By law, the IRS cannot discuss any specific taxpayer situation or case."