President Donald Trump sued Deutsche Bank and Capital One on Monday seeking to stop the banks from responding to subpoenas from Democrat-controlled Congressional committees.

The lawsuit claims that subpoenas from the House’s Financial Services Committee and Intelligence Committee lack any “legitimate or lawful purpose.” The committees issued subpoenas in April demanding documents related to Deutsche Bank’s loans and other banking relationships with Trump and his family.

“This case involves congressional subpoenas that have no legitimate or lawful purpose,” the lawsuit–filed on behalf of Trump, members of his family, and the Trump organization–claims. “The subpoenas were issued to harass President Donald J. Trump, to rummage through every aspect of his personal finances, his businesses and the private information of the president and his family, and to ferret about for any material that might be used to cause him political damage. No grounds exist to establish any purpose other than a political one.”

Representative Adam Schiff, the chairman of the Intelligence Committee, and Representative Maxine Waters, who heads the Financial Services Committee, issued a joint statement describing the Trump lawsuit as an attempt to “obstruct Congress’s constituti9onal oversight authority.”

Deutsche Bank reportedly lent over $3o0 billion to Donald Trump and his real estate businesses over the course of several decades. At one point, Trump sued Deutsche Bank over a soured loan. Later, however, the bank once again became a lender to Trump.

Trump’s lawsuit argues that the congressional subpoenas lack any legislative purpose and are merely intended to provide the president’s critics with ammunition to harass the president.

“No grounds exist to establish any purpose other than a political one,” the lawsuit claims.”For more than a century, in fact, the Supreme Court has been quite ‘sure’ that neither the House nor Senate ‘possesses the general power of making inquiry into the private affairs of the citizen,”

Deutsche Bank, based in Germany, is the 15th largest bank in the world and the largest lender in Germany, measured by assets. Its U.S. holding company has around $125 billion in assets, according to filings with U.S. regulators.

The bank became the primary bank lender to Trump’s businesses in the 1990s, at a time when other Wall Street firms had blacklisted him. Deutsche Bank, eager to grow its U.S. business, had a reputation for breaking ranks with Wall Street to do deals other firms shunned.

A Deutsche Bank spokeswoman issued the following statement: “We remain committed to providing appropriate information to all authorized investigations and will abide by a court order regarding such investigations.”