A survivor of the Florida school shooting has told National Rifle Association supporters attempting to discredit witnesses that they should give up as he and classmates “are going to outlive” them.

David Hogg has emerged as a powerful advocate for gun control after the Valentine’s Day attack at Marjory Stoneman Douglas High School in Parkland, which left 17 people dead.

His campaigning has however earned him a host of detractors, especially among pro-gun allies of the NRA, who have since launched a series of online attacks on teenagers who survived the bloodshed.

The 18-year-old and his classmates have been described as “pawns” who are being “coached” by activists aiming to restrict firearm ownership in the US.

Right-wing conspiracy theory-peddler InfoWars even received a strike against its largest YouTube channel, The Alex Jones Show, for uploading a video claiming the student was a “crisis actor”.

But in an interview with MSNBC’s AM Joy programme on Saturday, Mr Hogg responded to his detractors.

“The right is claiming that you are all being led around by celebrities, by George Soros, by the left,” host Joy-Ann Reid told the teenager, “your response?”

Mr Hogg replied: “I am so sorry to each and every one of you that is out there attacking us as witnesses and even some of the victims of this incident.

“It is truly saddening to see how many of you have lost faith in America because we certainly haven’t and we are never going to.

“You might as well stop now because we are going to outlive you.”

Police captured 19-year-old Nikolas Cruz at the scene of the shooting after a brief manhunt and later charged him with 17 counts of murder.

Florida shooting – in pictures Show all 10 1 /10 Florida shooting – in pictures Florida shooting – in pictures Police arrest a suspect in connection with the shooting at the Marjory Stoneman Douglas High School in Parkland, Florida Reuters Florida shooting – in pictures Parents wait for news after reports of a shooting at Marjory Stoneman Douglas High School in Parkland, Florida AP Florida shooting – in pictures Anxious family members wait for news of students AP Photo/Wilfredo Lee Florida shooting – in pictures Students being evacuated from the school AP Florida shooting – in pictures Students being evacuated from the school Getty Florida shooting – in pictures People gather waiting for word from students AP Florida shooting – in pictures Parents waiting for news on their children AP Florida shooting – in pictures People gather at a hotel where students were taken after the shooting Getty Florida shooting – in pictures Florida Governor Rick Scott speaks to the media as he visits Marjory Stoneman Douglas High School following the shooting AFP/Getty Florida shooting – in pictures Dr. Igor Nichiporenko, Medical Director Trauma, left, and Dr. Evan Boyer, Medical Director, Emergency Services, speak about treating victims and the suspect at a press conference outside Broward Health North hospital AP

An FBI information line transcript since released to the public revealed investigators were warned Mr Cruz had firearms and “was going to explode” in January.

The teenager allegedly ranted on social media in posts containing statements such as “I want to kill people”, in between sharing photographs of firearms.

The bureau has already admitted it failed to investigate a warning Mr Cruz had the capacity and desire to kill, leading Florida Governor Rick Scott to call for the resignation of FBI director Christopher Wray.