FILE PHOTO: Former White House adviser Sebastian Gorka (L), standing with White House counselor Kellyanne Conway (C), waits for U.S. President Donald Trump to arrive to board Air Force One for travel to Ohio from Joint Base Andrews, Maryland, U.S. July 25, 2017. REUTERS/Jonathan Ernst

LONDON (Reuters) - Sebastian Gorka, a former adviser to U.S. President Donald Trump who quit after top White House political strategist Steve Bannon was ousted, has joined a nationalist pro-Trump campaign organization, the group announced on Tuesday.

The MAGA Coalition, dedicated to helping advance Trump’s “America First” principles, said it had hired Gorka as “Chief Strategist.” MAGA is headed by Adam Gingrich, a Pennsylvania political operative who backed Trump’s presidential campaign.

A MAGA statement announcing Gorka’s appointment said its mission was to “identify the obstructionists in (Washington) DC and to advocate the America First principles that catapulted Donald Trump to the White House”.

It quoted Gorka, 46, as condemning “DC swamp-dwellers thinking they know better than the people they represent”.

Gorka has been an outspoken advocate of tough U.S. anti-terrorism policies and in the past asserted that U.S. efforts to counter Islamic State and other jihadist propaganda were “pin-pricks and often counter-productive”.

Prior to his time on Bannon’s White House team, Gorka was national security editor at Breitbart.com, the far-right website which Bannon headed before joining the White House and then rejoined after leaving the White House last month.

Gorka, the son of Hungarian refugees who was born in Britain, also previously taught classes at the U.S. Marine Corps University.

While at the White House, Gorka regularly appeared on cable news shows to promote Trump’s policies. But intelligence professionals and diplomats viewed him as an ideologue who lacked real-world experience.

In late August, the conservative Federalist website published a letter from Gorka saying he was resigning from the Trump Administration. But a White House official said in a statement: “Sebastian Gorka did not resign, but I can confirm he no longer works at the White House.”