"The requests single out President Trump because he is a Republican and a political opponent. They were made to retaliate against President Trump,” the filing said.
On Friday, acting Assistant Attorney General Dawn Johnsen said in a memorandum the Treasury Department must hand over Trump's tax returns to the US House Ways and Means Committee.
The Ways and Means Committee has requested six years of Trump's individual tax returns and tax returns of eight Trump-related businesses, the memorandum said.
The memorandum said the Ways and Means Committee is interested in obtaining Trump's tax returns in order to check the presence of any foreign financial influences, business entanglements concerning tax laws, or conflicts of interest that may have affected his responsibilities as US president.