Tory Brexiteer Daniel Hannan says he would have voted for Libertarian Party's Gary Johnson in US election

Mr Johnson famously did not know what the Syrian city of Aleppo was

Libertarian candidate in 2016, Gary Johnson (AP)

A leading Conservative Brexiteer has said he would have voted for the Libertarian Party candidate in the US presidential election.

Gary Johnson’s campaign famously went up in flames after a series of media appearances in which it became clear he had limited knowledge of the world.

In one excruciating exchange on the MSNBC channel in August Mr Johnson was asked what he would do about the massacres occurring in the Syrian city of Aleppo.

Mr Johnson replied: “What is Aleppo?” He had the situation explained to him by the host of the programme.

Mr Hannan, a Tory MEP has long campaigned for Brexit, made his choice clear during a tirade criticising people protesting against Donald Trump.

“I wouldn't have voted for Trump either. I was for Johnson. But why don't these youngsters like democracy? What system would they prefer?” he said, referring to a march of people protesting Mr Trump’s election.

Mr Johnson went on to make similar gaffes during the course of his campaign. Asked to name a foreign leader he admired he said he could not think of any.

He eventually settled on the “former president of Mexico” but said could not remember the man’s name.

The Libertarian Party candidate stood on a platform of sharp cuts to public spending and taxes, scrapping any government action to tackle climate change, and end to the limited state provision of healthcare in the United States.

Mr Johnson won 3.2 per cent of the vote