Yesterday was not a good day to be on trains in France, or Germany. Just as figures came out showing that both countries were enjoying exceptional economic growth (by recent standards), their trains, and much of daily working life, were brought to a standstill by strikes.

The governments of Nicolas Sarkozy and Angela Merkel have now entered a trial of strength with their transport unions. The result matters, not just for the defining character and survival of each government, but as the most explicit test for many years of whether, in each country, there is the popular support for necessary reforms to keep the economies competitive and to pay for an ageing population.

For Sarkozy, it will be the best test of whether six months of rhetoric about his determination to reform France’s public sector (among other missions) is really going to be followed by action. There must be some doubt about his ability to carry the cost-cutting pledges through to conclusion, for all the apparent gusto with which he has greeted the confrontation.

Yesterday only a fifth of high-speed trains were running, and transport services in Paris were limited. Gas and electricity workers interrupted power output; a third of universities were disrupted by students objecting to proposed charges for tuition. Next week hospital and school workers plan strikes over proposed job cuts.

There is no question about the underlying wisdom of Sarkozy’s proposals to cut the cost of public sector pay and pensions. Although economic growth is picking up, this year is still likely to fall short of government projections.

It was inevitable that there would be a clash between Sarkozy and the unions, and both sides raised the stakes by portraying the outcome as a crucial test of their strength.

But there must be doubt about whether it was wise to open battle on so many fronts at once. Hints of concessions have begun to trickle out, such as talk about not pursuing reform “that is just about pain”. That might herald a graceful compromise, preserving the best of his goals - or a climbdown.

For Merkel, already suffering the disintegration of her Right-Left coalition, in which resistance to her proposed reforms is a central strand, this week’s confrontation alone will not define her chancellorship. The three-day strike by freight train drivers, then passenger train drivers, is small compared with the French seizure, and is part of their recurrent demand for exceptional pay rises.

Resistance to her attempts to cut costs has already brought the unpromising Grand Coalition to the point of collapse. But as a spokesman said yesterday, the train strikes are a burden on “an otherwise positive economy”. Growth in 2006 was the fastest for six years. If there is public belief in the need for change, then that growth may ease the pain. Otherwise, it will defer the pressure, until the point when there is no choice.

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