Counterfeit currency is now so widespread in England that the government could soon be forced to reissue the one-pound coin, according to the Telegraph. While in 2002 1% of one-pound coins were fake, the figure is now 5%, or 1 in 20, and the quality of counterfeits is so high that most people can't tell the difference.

Metal Miner challenges readers -- Can you spot the fake below?

It's not crazy to think that citizens could lose faith in the coin already, given that other countries have run into currency confidence crises at far lower counterfeit rates.

At this level of counterfeit though it may become a necessity. [For the government to reissue everything.] Other countries have been forced down that route. The 5 Rand coin in 2004 was re-issued when taxi drivers and shopkeepers in South Africa refused to accept them – in South Africa the number of fakes was just 2% of those in circulation.

Again, note that the fake rate is 5% for one-pound coins. In the meantime, there could be a 'nice' black market arbitrage:

Anyone wanting to cheat the parking machines meter only has to lay their hands on a few Swazi lilangeni, minted from the same planchets as the British pound coin, and hence the Swaziland coin has the same chemical constitution, diameter, and mass. The lilangeni is only worth 11 to the pound at current exchange rates giving the user a handsome (if illegal) profit.

There has to be sufficient margin here to cover the cost of a plane ticket.

Oh, and here's the answer to the coin question:

The first is the fake and the second is a real Royal Mint coin. The edge detail on the first is not as clean and distinct as the real coin, and some fakes have the queens head on one side orientated out of alignment from the image on the reverse.