EU leaders insisted Friday that the Istanbul bomb blasts would not knock Turkey's EU hopes off course -- but the deadly attacks threaten to re-ignite debate over the vast Muslim country's candidacy.

The European Commission joined a number of foreign ministers including Britain's Jack Straw in declaring that the suicide attacks should have no impact on Turkey's hopes of winning a green light to start EU talks next year.

"Turkey's aspirations as a member of the EU are beyond any question," said Jean-Christophe Filori, a spokesman for EU Enlargement Commissioner Guenter Verheugen in Brussels.

"This should not in any way affect the reform process in Turkey. The (process) should be further pursued and enforced... The EU will do everything it can to support Turkey in that endeavour," he added.

But diplomats admitted in private that the attacks -- which come just as Turkey is embarking on reforms to improve its EU prospects -- will almost certainly be used by those opposed to Ankara's membership.

"There's no doubt that some of the old timers may well use this" to argue that Turkey is not ready for EU membership, said one, speaking on condition of anonymity.

Turkey has been an EU candidate since 1999 but, unlike the 12 other countries granted such status, it has yet to win a date to start accession talks.

The EU has demanded more progress from Ankara on key reforms notably involving human rights and treatment of its ethnic Kurdish minority.

Turkey's EU application has long fueled fierce debate -- centred on the impact of a Muslim country with such a different cultural background joining the expanding bloc, where Christianity is the dominant religion.

Former French president Valery Giscard d'Estaing, who chaired a convention drafting the EU's future constitution, infamously warned a year ago that Turkey's accession would mark the "end" of the EU.

And such arguments are far from dead in Europe, even if publicly EU leaders promote Turkey's hopes of joining the rich club, seeing it as a way to entice a country that spans Europe's border with Asia to pursue reforms.

In Germany, the government called on the EU to open its arms to Ankara after the attacks on British interests that killed 27, less than a week after attacks on two synagogues in the city left 25 people dead.

"Its value as a bridge should not be underestimated," said a Berlin government spokesman.

But many German conservatives are not so keen. Ingo Friedrich of the CSU, the sister party to Germany's main conservative opposition, said that trying to speed up Turkey's membership might only encourage more attacks.

Islamic extremists would be afraid that "a key country in the Islamic world is breaking away and joining the West," he told the Deutschlandradio station.

Britain's Straw, visiting Istanbul in the wake of the blasts, said: "We want to see Turkey coming into the European Union as a full member as soon as possible."

Italian Prime Minister Silvio Berlusconi, whose country holds the EU presidency, said Thursday that the attacks "will not succeed in distracting Turkey from its objective of being part of the European Union."

But former Turkish prime minister Tansu Ciller warned Friday that there were powerful forces who did not want Turkey to join the EU.

"The world has been restructured, and somebody wants -- or some groups want -- to stop Turkey from becoming part of the Western world and part of the European Union," she told the BBC in an interview.