The National Rifle Association (NRA) has pushed back against proposals by President Donald Trump to raise the age limit to buy certain guns, as the fierce debate over America’s gun control laws in the wake of the school shooting in Florida shows no sign of slowing.

Mr Trump has called for raising the age limit to buy certain types of guns – including the AR-15 assault rifle believed to have been used in the shooting – from 18 to 21 and banning bump stocks, which enable semi-automatic weapons to fire hundreds of rounds a minute. However, the country’s most powerful gun rights lobby group has said it does not back such a move.

“The NRA doesn’t back any ban,” spokeswoman Dana Loesch said on ABC’s This Week.

The interview comes amid a growing debate across America about gun control in the wake of the shooting at Marjory Stoneman Douglas High School in Parkland, with former student Nikolas Cruz, 19, having been charged with 17 counts of premeditated murder. Survivors of the shooting have filled the airwaves over the last 10 days calling for action over guns and threatening to vote out any legislator that does not back it.

Marjory Stoneman Douglas student David Hogg, 17, told the same programme that he believed the NRA is “an organisation that is a completely broken” and that Ms Loesch is not “serving the people of the NRA”.

Such high-profile and sustained calls for action appears to have shifted the public mood. According to a new CNN poll, 70 per cent of people now say they back stricter gun laws, up from 52 per cent who said so in an October poll not long after a mass shooting in Las Vegas killed 58 people. Support for stronger gun laws has not been so high in CNN polling since December 1993, with just 27 per cent of the more than 1,000 adults surveyed opposing stricter laws.

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

Facing calls for change, Mr Trump is seeking to take action without angering supporters who oppose gun control. As well as declaring his support for the age increase, and talking about stronger background checks – although without going into detail – he has conducted “listening sessions” at the White House about the issue.

Mr Trump was endorsed by the NRA during the presidential election and has often touted his support of the constitutional right to own guns. He is likely to tread carefully over the issue, particularly considering a number of companies have cut ties with the NRA after the Florida shooting.

Ms Loesch tried to play down the emerging differences between the NRA and the White House on Sunday. “I know that people are trying to find daylight between President Trump and five million law-abiding gun owners,” she said. “He’s really looking for solutions ... so far nothing’s been proposed yet.

“These are just things that he’s discussing right now,” Ms Loesch added

Democrats and Republicans who back more stringent background checks are hopeful that intervention from the President will help get changes through Congress. Republican Senator Pat Toomey of Pennsylvania, a sponsor of a bill that would require background checks for weapons sold at gun shows and on the internet, said the President could have a big impact.

“Our President can play a huge and in fact probably decisive role in this. So I intend to give this another shot,” Mr Toomey said on NBC’s Meet the Press.

Florida officer brought to tears recounting finding wife and kids during shooting

Legislation to close background check loopholes failed to clear the 60-vote threshold in the US Senate after a shooter killed 26 children and teachers in 2012 at an elementary school in Newtown, Connecticut.

Despite opposition to gun law changes within the Republican party, it is clear that the conservation over gun control has become harder to dismiss for some in the GOP.

Florida’s governor, Rick Scott, a long-time gun rights advocate, has also said he would endorse raising the age to purchase a rifle, along with a handful of other gun control compromises.

Mr Scott told Fox News Sunday: “You know, I’m an NRA member. I believe in the second amendment... I think most members in the NRA agree with me, this is logical. I’m sure there’s going to be some that disagree. But I’m a dad. I’m a granddad and I’m a governor. I want my state to be safe.”

Condoleezza Rice, former US Secretary of State under George W Bush, has also stepped into the debate.

“I think it is time for us to have a conversation about what the right to bear arms means in the modern world,” she said.

“I don’t understand why civilians need to have access to military weapons. We wouldn’t say you can go out and buy a tank,” Ms Rice told American radio talk show host Hugh Hewitt. “So I do think we need to have that conversation.”

The most controversial idea that Mr Trump has thrown his support behind, is possibly arming teachers in order to deter would be shooters. NRA spokeswoman Ms Loesch said the group – who had floated such an idea in 2012 – believes individual schools should decide whether to arm teachers.

The idea has sparked as much opposition as support – if not more – with Ms Rice a dissenting voice. “I don’t really like the idea, frankly, of a gun in my classroom,” she said.

She added: “I think that we need to have law enforcement protect us. Look, if people need to train people to protect our schools, and perhaps even communities want to consider whether or not they need guards to protect the schools... then that’s something that we should look at. But I don’t think that just arming people in the classroom is going to be the answer.”

Ms Loesch said more emphasis should be placed on how the FBI and local police – the Broward County Sheriff’s Office – missed warning signs and tips about the alleged shooter, calling it an “abdication of duty”.

Responding to such criticism, Broward County Sheriff Scott Israel said on Sunday he would not resign and that an investigation was being conducted into how tips and reports that had been received before the shooting were handled.

One sheriff’s deputy who was at the scene, Scot Peterson, resigned after being placed on leave for not entering the school building to confront the shooter as gunfire was happening. The actions of the armed deputy seems to at least partially undermine Mr Trump’s argument for putting more guns in schools and Mr Israel said he would investigate any other reports of inaction.

“I was disgusted. I was just demoralised with the performance of former deputy [Scot] Peterson,” Sheriff Israel told CNN.