By Rich McKay
April 30 (Reuters) - President Donald Trump, his three oldest children and the Trump Organization have sued Deutsche Bank AG and Capital One Financial Corp to try to block them from responding to subpoenas issued by U.S. congressional Democrats seeking financial records.
The lawsuit represents a new front in Trump's battle with the Democratic-led House of Representatives to impede investigations of the Republican president, his family, his businesses and his administration following Special Counsel Robert Mueller's inquiry into Russia's role in the 2016 election.
In a complaint filed on Monday night in federal court in Manhattan, Trump and his family accused House committee leaders of pursuing the records for no legitimate or lawful purpose. Only the banks were named as defendants.
"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," the complaint said.
The lawsuit also accused Democratic leaders of hoping to "stumble upon something they can expose publicly and use as a political tool against the President."
Representative Maxine Waters, who chairs the House Financial Services Committee, and Representative Adam Schiff, who chairs the House Intelligence Committee, called the lawsuit "meritless" in a joint statement, according to media reports.
Deutsche Bank has long been one of the main banks for Trump's real estate empire. Deutsche Bank said in a statement, "We remain committed to providing appropriate information to all authorized investigations and will abide by a court order regarding such investigations."
Capital One was not immediately available for comment.
On April 15, two House committees issued subpoenas to multiple financial institutions for information on Trump's finances.
Trump, who is seeking re-election next year, has said he intends to defy efforts by congressional Democrats to look into his affairs, including possible dealings with Russia.
The complaint by Trump, his adult children Donald Jr., Eric and Ivanka, and the Trump Organization said House leaders ignored constitutional limits on Congress' power to investigate, and any probe needed to further some "legitimate legislative purpose" and could not be an end in itself.
It also said the subpoenas violated the plaintiffs' privacy rights, and the refusal of House committees to even provide copies of the subpoenas to the plaintiffs made it impossible to know, or negotiate, their scope or breadth.
The plaintiffs said Deutsche Bank confirmed that the subpoenas it received sought financial information for their "parents, subsidiaries, affiliates, branches, divisions, partnerships, properties, groups, special purpose entities, joint ventures, predecessors, successors or any other entity in which they have or had a controlling interest."
Lawyers for the plaintiffs were not immediately available for comment.
Mueller's report detailed extensive contacts between Trump's campaign and Russia and described the campaign's expectation of benefiting from Moscow's actions, but did not conclude there was a criminal conspiracy. (Reporting by Rich McKay; Additional reporting by Jonathan Stempel; Editing by Richard Pullin and Will Dunham)