Its not just the British military who are having budget difficulties. Our current "fiscally prudent" chancellor committed himself to taxing and spending plans that now seem imprudent given the economic downturn.
His attempt to minimize tax increases while increasing spending was working while Britain's economy boomed, but now he seems to be just crossing his fingers for an upturn = trouble
As for Britain's military, well, it is still having difficulties transitioning from its cold war role. It was designed and equipped to basically sit around and wait for 'the big one' - ie land and air war in Europe and convoy duties in the Atlantic.
Today its role seems to be to provide 5 or 6 peacekeeping missions and one major invasion a year - very expensive and manpower intensive ops, and ops that its mbts and anti-submarine aircraft carriers aren't really fitted for.
At the same time it is paying loads of money for new weapon systems and programs that were designed during, and specifically for, the cold war, like the Eurofighter - designed to win aerial superiority over germany, and now hastily being rejigged to have some use in actions like Iraq/Bosnia/Afghanistan etc. Its no wonder they are having difficulties