But following "no" votes in France and the Netherlands, the constitution remains in the deep freeze and this vote will not change the outlook of several nations - including Denmark and the UK - that have shelved referendum plans. To come into force, the constitution must be approved by all 25 member states.
A founder member of the EU, the Grand Duchy of Luxembourg has a population of about 460,000 and houses several European institutions, including the European Court of Justice.
With a significant part of its economy linked to the EU, a "no" vote in Luxembourg would have been a big surprise, though a close result had been predicted. Some "no" campaigners sought to exploit unease at Turkey's ambitions to join the EU, while the left presented the constitution as an attack on the European social model with generous welfare standards.
The most direct effect of the vote was to avert political upheaval in Luxembourg, where Mr Juncker had staked his future on the result. The 50-year-old centre-right premier is the dominant force in the country's politics, and is also the finance minister. A chain-smoker, hardened drinker and supporter of closer European integration, Mr Juncker has a reputation as a skilful negotiator. But a summit which he chaired in Brussels last month broke down in acrimony, and Mr Juncker made it clear he blamed Tony Blair for blocking a deal on how to fund the EU.
The same summit agreed to allow governments to put aside plans to ratify the constitution, if they wished, for a period of reflection. The Luxembourg parliament, which had called for a plebiscite, decided to continue with its poll, however.
Before yesterday the charter had already been ratified by 12 countries, the latest being Malta, but there are no moves to overturn the negative votes in France or the Netherlands.
Last night, the European Commission's president, Jose Manuel Barroso, said the fact that 13 countries had already approved it "shows a majority of member states believe the consitutional treaty meets their expectation".Reuse content