Inflation cannot be zero. Inflation is required for economic growth. At present UK inflation is 2.2% and not 3%. Germany is a industrial base, so is UK a financial hub. Do you know that $1 trillion dollars are raised and invested every year for The City alone, a one square KM space in midst of London. Imagine the transaction fee these investment companies generate.
And remember, this is a economic forecasting, not some kind of prediction. The reality can be quite different.
I guess the main reason for this kind of economic forecasting is 1)Younger demographics of UK as compared to Germany 2)Having its own currency gives UK a hard power to control its economy in harder time 3) With Germany being the centre of Euro Zone, it has to take along with it the Euro lags such as Portugal, Greece etc...in this Economic race. UK has no such obligation.