Like their counterparts across the pond, British conservatives entered office in 2010 as firm believers in fiscal austerity, slashing spending, curbing public investmentand raising food, electricity and tuition costs. Echoing the views of many Republicans, Britain’s Chancellor of the Exchequer, George Osborne, predicted that “expansionary austerity” was just the cure for the country’s economic crisis.

It turns out that austerity in Britain, like in the rest of the world, has been anything but expansionary. “The empirical case against expansionary austerity is that it doesn’t seem to be working in Britain (or in any of the struggling eurozone countries),” notes Larry Elliott, economics editor of the Guardian. Since the Tory-Liberal Democrats coalition took over, economic growth has slowed, unemployment has increased and investor confidence has plummeted.

As in the United States, public sector employees have bore the brunt of the recession. Their pay has already been frozen for two years and now the government has proposed capping wage increases at 1 percent beginning in 2013 (a cut in real terms), while demanding that public sector workers increase their pension contributions by 3 percent and retire two years later. Britain’s independent Office of Budget Responsibility predicted yesterday that more than 700,000 public sector workers would lose their jobs by 2017.

It’s against this backdrop that public sector workers staged the largest strike in three decades today, with 2 million workers protesting the government’s cuts. The Guardian called it “the biggest bout of industrial action since the 1979 winter of discontent.” (Check out the paper’s live coverage.)

“Public sector workers are justified in striking since they’re being asked simultaneously to work longer, get a smaller pension, and put in a higher contribution,” says Will Straw, an economic policy expert at Britain’s Institute for Public Policy Research. “The Government has left the Unions with no choice.… The Unions need to ensure now that they build public support for their argument but also explain why the Government’s policies will detrimentally affect those working in other sectors by consigning the UK to meager pensions, second rate public services, and further austerity.”

The strikes are designed to put pressure on the government to negotiate a fairer deal, draw public attention to the perils of austerity and push the opposition Labour Party to take a stronger stance against the government’s cuts and in favor of public investments. There are signs the Labour Party, under new leader Ed Milliband, is heading in that direction. Milliband criticized an earlier bout of strikes in June, angering the unions who supported his bid for party leader, but defended the striking workers today. “Why do you think so many decent, hard-working public sector workers, many of whom have never been on strike before, feel the government simply isn’t listening?" he asked Prime Minister David Cameron today.

Today’s strikes mark the largest protest against the government’s austerity regime, but they certainly won’t be the last. The policies of the coalition government are likely to grow only more unpopular if the economy continues to head south. Austerity usually leads to a vicious, self-defeating circle, Paul Krugman notes:

What’s happening in Britain now is that depressed estimates of long-run potential are being used to justify more austerity, which will depress the economy even further in the short run, leading to further depression of long-run potential, leading to…

It really is just like a medieval doctor bleeding his patient, observing that the patient is getting sicker, not better, and deciding that this calls for even more bleeding.

And the truly awful thing is that Cameron and Osborne are so deeply identified with the austerity doctrine that they can’t change course without effectively destroying themselves politically.

As the Brits would say, brilliant. Just brilliant.

US politicians, take note. Don’t say you haven’t been warned.