Steve Bannon has said it will “be the end of everything” for Donald Trump if he supports gun control in the wake of the worst mass shooting in US history.

At least 59 people are dead and 515 injured after a gunman fired on a crowd of concert-goers from the 32nd floor of the Mandalay Bay hotel in Las Vegas.

The President has been a staunch supporter of the Second Amendment, and avoided addressing the issue of gun rights during a White House speech condemning the “pure evil” attack.

But Mr Bannon has warned the billionaire his core supporters would react in horror if he were to back any move to restrict access to firearms, according to Axios.

Asked if Mr Trump’s base would respond even more negatively to him tightening gun laws than supporting an immigration amnesty bill, the White House Chief Strategist said: “As hard as it is to believe [it is] actually worse.”

Roger Stone, another former adviser to Mr Trump, told Axios his supporters would “go insane and he knows it”.

Since becoming President, the 70-year-old has begun rolling back restrictions on gun ownership, despite calling out Republicans who “walk the NRA line” in his 2000 book The America We Deserve.

In February he signed an order blocking an Obama-era rule that would have stopped an estimated 75,000 people with mental disorders from buying firearms.

Las Vegas shooting – in pictures Show all 15 1 /15 Las Vegas shooting – in pictures Las Vegas shooting – in pictures People scramble for shelter at the Route 91 Harvest country music festival after gun fire was heard Getty Las Vegas shooting – in pictures People carry a person at the Route 91 Harvest country music festival after shots were fired David Becker/Getty Las Vegas shooting – in pictures People run from the Route 91 Harvest country music festival after gun fire was heard David Becker/Getty Las Vegas shooting – in pictures A handout photo released via Twitter by Eiki Hrafnsson (@EirikurH) showing concertgoers running away from the scene (C) after shots range out at the Route 91 Harvest festival on Las Vegas Boulevard EPA/Eiki Hrafnsson Las Vegas shooting – in pictures People lie on the ground at the Route 91 Harvest country music festival after hearing gun fire Getty Las Vegas shooting – in pictures A man in a wheelchair is taken away from the Route 91 Harvest country music festival after hearing gun fire David Becker/Getty Las Vegas shooting – in pictures People stand on the street outside the Mandalay Bay hotel near the scene of the Route 91 Harvest festival on Las Vegas Boulevard EPA/Paul Buck Las Vegas shooting – in pictures FBI agents confer in front of the Tropicana hotel-casino after a mass shooting during a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures Las Vegas police run by a banner on the fence at the Route 91 Harvest country music festival grounds after shots were fired David Becker/Getty Las Vegas shooting – in pictures An injured person is tended to in the intersection of Tropicana Ave. and Las Vegas Boulevard after a mass shooting at a country music festival Ethan Miller/Getty Las Vegas shooting – in pictures Metro Police officers pass by the front of the Tropicana hotel-casino after a mass shooting at a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures A woman sits on a curb at the scene of a shooting outside of a music festival along the Las Vegas Strip AP/John Locher Las Vegas shooting – in pictures A cowboy hat lays in the street after shots were fired near a country music festival in Las Vegas Getty Las Vegas shooting – in pictures Las Vegas Metro Police and medical workers stage in the intersection of Tropicana Avenue and Las Vegas Boulevard South after a mass shooting at a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures Sheriff Joe Lombardo (2-R) speaking during a press briefing in the aftermath of the active shooter incident on Las Vegas Boulevard EPA

And in April, he told National Rifle Association members: “The eight-year assault on your Second Amendment freedoms has come to a crashing end.”

The reality TV mogul also assured the association, which donated more than $30m to his presidential campaign, that it now had a “true friend and champion in the White House”.