Boris Johnson has rejected as “complete hysteria” the suggestion he is a right-wing populist.

Speaking at a Conservative leadership hustings in Northern Ireland on Tuesday afternoon, the frontrunner to succeed Theresa May said people had said “extraordinary things” about his views.

“I remain a proud, free market, low-tax Conservative. I just happen to think our country does better when we send out a signal to the world that we are inclusive and tolerant and generous in our approach to other people,” he said.

Johnson denied he is a populist, adding: “I don’t know where it all comes from.”

The former foreign secretary has previously used his Daily Telegraph column to refer to black people as having “watermelon smiles”, using the offensive colonial-era term “piccaninnies”. He once described Barack Obama as a “part-Kenyan president”.

He has also described women who wear the burka as looking like “letterboxes”.

Johnson has also been forced to deny as the “biggest load of codswallop” the claim Steve Bannon, the former senior adviser to Donald Trump, has previously advised him.

Speaking to Tory members on Tuesday, Johnson also said claims a no-deal Brexit would be damaging to the UK economy were “wildly over-done”.

“We should not be terrified of coming out on WTO terms,” he said. “I prophesy very confidently that we will have a successful Brexit, the planes will fly, there will be clean drinking water.”

It came as Chancellor Philip Hammond warned he would try to “ensure” a no-deal Brexit did not happen if, as expected, he returns to the backbenches once a new Tory leader is chosen.

“I think I have been consistently clear that I believe leaving with a no-deal exit will be bad for the UK, bad for the British economy, bad for the British people,” told MPs.