In Germany it may look as though nothing changes but beneath the apparently smooth path to re-election of Chancellor Angela Merkel, the tectonic plates of German politics are shifting ominously.

There is little doubt that Merkel will remain chancellor after the German elections next weekend, her solid lead in the opinion polls reinforced by a strong result for her sister party in Sunday's Bavarian elections. But the real significance of the regional election in the rich and powerful province was the collapse of the Free Democratic Party, Merkel's coalition party in the national government.

The FDP polled less than 4 percent of the vote, a catastrophic result in Germany since the threshold for getting seats in Parliament is 5 percent.

The FDP has long held the balance of power, able to help either Merkel's conservatives or the centre-left Social Democratic Party, known by its German initials of SPD, to cobble together a majority in the Bundestag in Berlin.

Analysts are scratching their heads as they ponder one of two outcomes. Either the FDP disappears from national politics or, under Germany's complex two-vote system (one for a candidate, the other for a party list), many of Merkel's own Christian Democratic Union members will shift their party vote to the FDP to keep it alive.

But that could so erode Merkel's vote that she could have little option but to turn to another party for the extra seats she would need for a stable majority.

All this means that the most likely next German government will be another grand coalition of Merkel's party (known as the Blacks) and the Social Democrats, (known as the Reds). Such a Red-Black coalition is quite common in Germany; Merkel's first term as chancellor was leading such a Red-Black government. But it tends to mean the bland politics of the lowest common denominator, with few tough or controversial decisions.

This could suit Merkel, who had made an art of the politics of placid reassurance and no surprises. Outside Berlin's main train station there is a giant poster of her two hands, the fingers just touching in a familiar pose. The message is that Germany is safe in her hands.

That may have been what inspired her SPD opponent Peer Steinbruck to provoke a media flurry by having himself photographed giving what Germans call "the stinky finger" on the front-page of a magazine.

In fact, Germany faces three serious crises, not one of which has really been addressed in the campaign.

First, there is the crisis of the euro and Merkel has been forced to admit that Greece will probably need another bailout. Despite mildly improved economic output in France, the eurozone outside Germany remains depressed. Spain's debt has reached record levels and Italy continues to decline. And as global interest rates creep up, Europe's debt crisis will only worsen.

Second, there is the energy crisis, with sky-rocketing electricity prices because of subsidies for wind and solar power. At the same time, Merkel's attempt to win a regional election two years ago by announcing the closure of Germany's nuclear power stations has proved disastrous. Germany now has to import electicity, produced by French nuclear power stations, from France. Germany is also importing cheap coal from the United States, which means its carbon emissions are higher now than they were a decade ago. Such much for Merkel's green credentials.

Third, there is the demographic crisis, with Germany aging fast and producing too few children to staff the economy in the future. This means that Europe, which hinges on a strong German economy, faces an even stiffer challenge for the future. Merkel likes to boast of a Europe that has only 7 percent of the world's population but is responsible for 50 percent of the world's social spending. Europe will find it tough to maintain this generous welfare state.

Merkel ducked all these issues and the election has focused instead on whether there should be a meatless "veggie day," on extra benefits for stay-at-home mothers and on a minimum wage. The SDP is for it, Merkel against.

The real problem with the grand coalition is that it will be inherently unstable. Within two years, its component parties and their leaders will be jockeying for position for the next elections.

But who will be the leaders? Merkel has apparently told colleagues that this should be her last term as chancellor and she may not even finish it.

But one of the characteristics of Merkel's politics has been the ruthless destruction of any emerging rival from within her own party ranks. She has no obvious heir, so the in-fighting will be intense. The Social Democrats are about to undergo a generational shift in their aging leadership and the young hopefuls will need to make an effective impact in whatever ministerial jobs they might get in a grand coalition.

Der Spiegel magazine reports pollsters are finding that around 30 percent of voters have yet to make up their minds and plan to do so this week. They seem most unlikely to ditch Merkel but haven't yet decided whether they will allow her to govern untrammeled by a grand coalition with the Social Democrats.

Either way, German politics is heading for bumpy times.