The BBC has been heavily criticised for inviting one of Donald Trump’s most controversial former aides on to its flagship radio news programme.

Sebastian Gorka appeared on BBC Radio 4’s Today programme to respond to the resignations of two Republican senators who launched blistering attacks on the President. Mr Gorka called Bob Corker and Jeff Flake “cowards” and suggested they were not “true conservatives”, even expanding his criticism to George W Bush after he sounding a warning over bigotry and white supremacy.

Batting away repeated criticisms of Mr Trump’s treatment of fact and attacking “fake news”, he claimed: “There’s a theme of irrelevant individuals trying to make good on their failures.”

But listeners were quick to point out that Mr Gorka himself holds no political office after resigning from the White House.

Many argued he should not have been given airtime after another interview where he blamed “black African crime” for shootings in the US.

The London-born strategist left his White House post in August after reportedly being fired out by new Chief of Staff John Kelly, following mounting disquiet over his right-wing views and questionable credentials.

Long ridiculed by security experts and criticised for his position on Islam, he was forced to deny allegations of neo-Nazi links after wearing a medal awarded to his father by Hungary’s Order of Vitéz.

Before being taken in by the Trump administration, Mr Gorka unsuccessfully ran for a mayoral post in Hungary and tried to launch a nationalist political party, later moving to the US and starting counter-terrorism think tanks.

Sebastian Gorka defends wearing a medal linked to Hungarian Nazi sympathisers

From 2011 to 2013, he was an adjunct assistant professor teaching national security at Georgetown University, prepared reports for the Boston Marathon bombing trial and became the national security editor for Breitbart News.

Controversy over Mr Gorka’s appearance on Today came after the BBC’s complaints unit found it should have challenged the views of a climate change sceptic in August. Appearing on the same show, Lord Lawson argued that “official figures” showed average world temperatures had “slightly declined” – a claim shown that was shown to be false by the Met Office but not challenged on air. The BBC admitted it had breached its “guidelines on accuracy and impartiality” in that instance.