The UK Debt Management Office website shows that a UK Treasury bond offering 5% annual interest is, because of its current traded price, actually yielding 2.522793%.
But the risk of default, almost as high as Italy's government debt and far higher than even the USA's, is (as Jesse quotes) currently priced at 1.63%. (The market currently prices the risk of USA default at 1%.)
So after insuring for risk, 5-year UK sovereign debt earns you less than 0.893%.
Inflation, as measured by the Consumer Price Index*, now runs at 3%. In other words, a "safe" government bond loses you more than 2% a year.
And that's before inflation really gets going.
*The Retail Price Index is a different measure of inflation, which takes into account mortgage costs. So after recent savage cuts in the bank rate, currently RPI should be negative. But wait until the private capital credit strike leads to higher interest rates, and judge.