French 10-year yields came close to 5% on 2 October, their highest since 2002, as a global bond selloff met fresh doubts about France's budget.

They've eased a little since, but France now borrows at roughly the same rate as Italy, and the spread over Germany had just posted its biggest weekly jump in more than three decades.

France hasn't balanced its budget since the 70s, and its debt, roughly level with Germany's when the financial crisis hit, is now edging towards Italy's.

Parliament has just started debating next year's budget while high-school students blockade schools across the country. With a presidential election in April, few in opposition want their fingerprints on the cuts.

Rassemblement National could let the budget through as a stopgap and promise one of its own once in power, and Marine Le Pen has just pledged even deeper spending cuts if elected. If the government falls instead, France would roll this year's budget into next year, with the deficit even wider.

But even if some of the recent selling unwinds, France now pays more on new 10-year debt than its economy grows in cash terms, after most of a decade the other way round. As older, cheaper debt rolls over, the interest bill grows faster than the economy paying it.

Whichever way the vote goes, the budget that really matters will probably be written after the election, and France will be refinancing at these rates until then.