WASHINGTON • President Donald Trump's former chief strategist Stephen Bannon was unsparing in his criticism during his first extended interview since leaving the White House: He called out top Republicans, West Wing staff, the "pearl-clutching mainstream media", special counsel investigators and the Roman Catholic Church.

He even singled out Mr Trump, labelling his firing of former Federal Bureau of Investigation (FBI) director James Comey the biggest mistake in "modern political history".

Mr Bannon said had Mr Comey not been fired, the Justice Department investigation into possible links between the Trump campaign and Russia's election interference would not have been handed over to the special counsel, Mr Robert Mueller, who is said to be investigating whether Mr Trump obstructed justice in firing the FBI chief.

"We would not have the Mueller investigation and the breadth that clearly Mr Mueller is going for."

The assertion, made in an online- only segment of a 60 Minutes interview aired in the United States on Sunday night, was perhaps the most extraordinary of many criticisms Mr Bannon made as he set out to reclaim his mantle as Mr Trump's most prominent outside supporter from his perch as the head of far-right website Breitbart News.

He also called the special counsel a "waste of time", saying: "Russian collusion is a farce."

Mr Bannon said he planned to be the President's "wingman outside for the entire time" he is in office.

"I cannot take the fight to who we have to take the fight to when I'm an adviser to the President, as a federal government employee."

Mr Bannon left the White House on Aug 18 after a year first as Mr Trump's campaign chief and then as his chief strategist.

Among those Mr Bannon plans to take on now are House Speaker Paul Ryan and Senate majority leader Mitch McConnell, two Republicans he accused of "trying to nullify the 2016 election".

"They do not want Donald Trump's populist, economic nationalist agenda to be implemented."

Mr Bannon predicted deep division within the Republican Party over Mr Trump's recent move to end temporary relief from deportation for thousands of young people in the US illegally. The President has asked Congress to come up with a solution, a task that Mr Bannon said could split Republicans and cost them their House majority in the 2018 mid-term elections.

When interviewer Charlie Rose asked whether Mr Bannon's opposition to the immigration programme was true to his Catholic faith, Mr Bannon took aim at church leaders, saying: "They need illegal aliens to fill the churches."

Cardinal Timothy Dolan, archbishop of New York, called Mr Bannon's comments "preposterous and rather insulting".

Mr Bannon also condemned top officials in the George W. Bush administration, calling them "idiots", friendly to what he termed China's anti-American economic agenda. He singled out former secretaries of state Condoleezza Rice and Colin Powell, criticising them for China's 2001 entry into the World Trade Organisation.

"They've gotten us in this situation, and they question a good man like Donald Trump," he said.

Mr Bannon also said he was the President's only defender after the racially tinged violence in Charlottesville, Virginia, last month, when Mr Trump was widely condemned for statements that likened white supremacists to people protesting against them. Yet he accused neo-Nazis of "getting a free ride off Donald Trump" for their role in white supremacist rallies.

NYTIMES