Secretary of Homeland Security Kirstjen Nielsen speaks during a White House daily news briefing at the White House in June.  (Photo by Alex Wong/Getty Images)
CNN  — 

A tense fight between House Democrats and President Donald Trump’s administration over Cabinet officials resisting testifying on Capitol Hill escalated Wednesday when the House Homeland Security chairman warned he would not hesitate to issue a subpoena for Homeland Security Secretary Kirstjen Nielsen to appear before his panel.

Rep. Bennie Thompson, a Mississippi Democrat, sharply criticized Nielsen for refusing to testify February 6 though the Department of Homeland Security said she is open to other dates and that she had proposed alternate dates in February. On Tuesday night DHS Press Secretary Tyler Houlton strongly disputed that Nielsen had refused to testify, saying “she accepted the