Coinbase has found an unlikely ally in its fight to keep the U.S. Internal Revenue Service from getting its hands on the digital currency exchange’s customer transaction records—the Republicans.

Last week, Senior GOP members sent a sharply-worded letter to IRS Commissioner John Koskinen, telling him that the tax agency may have been overstepping its powers in the probe into possible tax fraud committed by U.S. residents who engaged in business with or through the San Francisco-based bitcoin exchange.

The California district court allowed IRS to require Coinbase to submit records of all transactions that took place from 2013 to 2015, but the bitcoin company has taken the fight to block the summons back to court, where it was recently joined by two anonymous customers.

Now, Sen. Orrin Hatch (R-Utah), chairman of the Senate Finance Committee, and Vern Buchanan and Kevin Brady, heads of the House Committee on Ways and Means, have added more ammunition to Coinbase’s firepower.