The National Rifle Association said people were concerned about self defence because police officer numbers were declining.

A spokesman said: "I think there's an increased realisation that when something bad occurs it's going to be between them and the criminal."

But anti-gun campaigners said those who already owned weapons were simply hoarding more of them due to "fear-mongering" by the NRA.

A spokeswoman for the Brady Campaign to Prevent Gun Violence said: "The research we've seen indicates fewer and fewer people are owning more and more guns."

Dave LaRue, of Legendary Guns in Phoenix, Arizona, said Christmas sales were up 25 per cent on the previous year and ammunition sales were also "brisk".

He said: "There are a lot of people concerned about pending gun legislation and the sense about the current administration. People think future availability will be limited and there's a feeling of get it while you can."

The record for gun sales in a single day was set in November, on the day after Thanksgiving, when 129,166 background searches were carried out on customers buying weapons.

Since the near-fatal shooting of congresswoman Gabrielle Giffords by a deranged gunman in Tucson, Arizona last January there have been increasing calls for tighter gun control. Miss Giffords survived being shot in the head with a semi-automatic handgun, and six other people were killed.