AS Southampton Itchen MP Royston Smith announces he is stepping down at the next general election, we look back on an extraordinary moment in his political career.

Mr Smith was the leader of Southampton City Council when he helped disarm a sailor who started shooting fellow crewman aboard a nuclear submarine in the city.

Mr Smith, who was visiting HMS Astute, was just five yards away from Able Seaman Ryan Donovan when he fired six shots from an SA80 rifle in the control room in 2011.

READ MORE: Fatal shooting in HMS Astute in Southampton 

Lt Cdr Ian Molyneux, 36, was shot dead before Mr Smith and the council's chief executive, Alistair Neil, could wrestle the gunman to the floor.

They were later presented with the George Medal by the Queen. Donovan, 22, was jailed for at least 25 years for murder and three counts of attempted murder.

Daily Echo: HMS AstuteHMS Astute (Image: Ministry of Defence)

Mr Smith, a former RAF engineer who served in the Falklands, suffered cuts and bruises as he fought to restrain the gunman and remove his rifle.

READ MORE: Ryan Donovan was twice drink-drive limit during HMS Astute shooting spree, inquest told

Speaking to the Daily Echo shortly after the incident, the politician said he thought he was going to die.

"A chap turned up in the doorway with his body armour on and carrying his SA80, but there were no dramas because that is nothing out of the ordinary," he said.

"Somebody asked him what he was doing and he stepped back and disappeared from my view.

"Then I heard a shot ring out. I thought the weapon had been accidentally discharged, but then think I heard someone shout and a second shot followed and I instantly knew it wasn’t accidental.

Daily Echo: Royston Smith pictured during a visit to Southampton Engineering Training AssociationRoyston Smith pictured during a visit to Southampton Engineering Training Association (Image: Newsquest.)

"A couple of seconds later he appeared back at the doorway. He levelled the rifle towards us all.

READ MORE: Royston Smith describes fatal shooting aboard HMS Astute in Southampton docks

"The third shot came out and then I heard the hiss right next to me and thought, ‘well, that’s it’.

"I didn’t think about myself at first, I just thought he was going to keep shooting into the room and everyone was going to end up dead.

"Everybody froze, but then I ran at him. I grabbed the rifle and pinned him against the wall.

"I spun him 180 degrees and managed to slam him into the opposite wall. I think there was another shot while I was still trying to get the gun off him but he was holding it tightly, with his finger firmly on the trigger.

"The next thing was I had the rifle in my hands and threw it under a table out of reach. He was on the floor when I took it from him.

READ MORE: Ian Molyneux was killed trying to tackle Ryan Donovan aboard HMS Astute

"He was quiet throughout – I was the one shouting as I went for him. I knew the trick was to make yourself as scary as possible, I was definitely making all the noise.

"He had been stood just four or five yards from me and I definitely thought there was a very real chance it was going to all go wrong. It crossed my mind because I couldn’t disarm him straight away that it might not end well for me, he might kill me.

Daily Echo: HMS Astute docks in Southampton in 2011HMS Astute docks in Southampton in 2011 (Image: Newsquest.)

"He wasn’t a giant of a guy but he had hold of that gun firmly because it took me two good shoves to get it from him.

"Once he was on the floor Alistair came into his own. I was shouting at this point because I saw a second person, dressed in civvy clothes, who for that moment I thought was another gunman. I was shouting to Alistair to help me keep the man on the floor as he was struggling, kicking like a mule, so he sat on him."

READ MORE: Ryan Donovan accused of murder

A group of schoolchildren had been on board the vessel just a short time before.

Mr Smith said: "As I tried to unscramble all of this in my mind I could clearly see all those school kids stood there, right by where he opened fire.

"The reality was they had left almost half an hour earlier and you have to be thankful they were not still in there to witness it.

"I’m not a religious man but it's certainly made me think that maybe there is something about realising when your time is up."

Emergency services had raced to the scene following a 999 call at 12.09pm.

Police imposed a 50-metre cordon around the area and closed off access to the docks close to the QE2 terminal as investigations got underway.

Daily Echo: Royston Smith abseils down the side of Canberra Towers in aid of the Jubilee Sailing TrustRoyston Smith abseils down the side of Canberra Towers in aid of the Jubilee Sailing Trust (Image: Newsquest.)