"In response to the subpoenas issued by the New York County District Attorney, we have filed a lawsuit this morning in federal court on behalf of the President in order to address the significant constitutional issues at stake in this case," Trump attorney Jay Sekulow said in a statement, according to Bloomberg. 

The subpoena was issued by the Manhattan DA's office last month following the launch of a criminal investigation into hush-money payments made to porn star Stormy Daniels (real name Stephanie Clifford) by former Trump attorney Michael Cohen - who pleaded guilty last year to eight charges; seven of which were unrelated to the Trump campaign, and one for breaking federal campaign finance laws. He is currently serving a three-year prison sentence. 

Vance's office wants to determine whether Trump's accounting firm falsely accounted for Cohen's reimbursements as a legal expense.