Barroso: EU moving too slow on debt crisis

"It is essential ... that we move forward rapidly with the implementation of all of that has been agreed by the heads of state and government and send an unambiguous signal of the euro area's resolve to address the sovereign debt crisis," he added. "Tensions in bond markets reflect a growing concern among investors about the systemic capacity of the euro area to respond to the evolving crisis."

Eurozone leaders at a summit in July agreed to change the terms of the currency club's €440 billion bailout fund so that it could in future act pre-emptively to avert Greek-type financial meltdowns.

But national parliaments opted to break for their summer recess instead of ratifying the measures, leaving investors wondering how or if they will work in practice.

Rainer Guntermann, a strategist at Germany's Commerzbank, told EUobserver on Wednesday that this uncertainty is part of the reason for jitters on Italian and Spanish bonds: "The markets were disappointed by large countries who did not want to vote now but took their summer vacations instead of coping with the crisis. This has created an implementation risk."

Another contact at a large Swiss bank, who did not want to be named, added: "Market participants are not trusting enough about whether the new measures will really work if they are needed ... The decisions have been made, but they haven't seen the new system working properly on an operational level."

Neither Italy nor Spain are facing imminent problems with debt repayment. But a number of other concerns about the health of the eurozone as a whole are also playing a part in bond spreads.

Markets fear that if Ireland and Portugal need second bailouts, private creditors will be made to pay part of the cost, as in Greece, creating general aversion toward non-AAA-rated eurozone debt. Weaker-than-expected economic performance by the US is also casting doubt on the global economic recovery, auguring lower growth and less money in the public pot in peripheral euro-using countries.

Meanwhile, the choice of words by EU officials is itself proving unhelpful.

EU Council chief Herman Van Rompuy on Tuesday said he was "astonished" at the Italian and Spanish bond moves. "'Astonished?' - this element of surprise suggests you are not prepared. The statements suggest Europe is moving too slow for the markets right now," Commerzbank's Guntermann said.

For his part, Italian leader Silvio Berlusconi will at 5.30pm local time tell parliament how he plans to put his country on a sound financial footing.

The move follows a meeting between his finance minister Giulio Tremonti and eurozone president Jean Claude Juncker in Luxembourg earlier the same day after which Tremonti said only: "We had a long and fruitful discussion."

Commentators noted that Berlusconi will need to announce concrete measures - such as bringing forward previously-tabled austerity cuts from 2013 to 2012 or 2011 - if his speech is to have a positive impact. "A kind of general pep talk will not be helpful ... anything other than specific actions will be seen as a non-event," the Swiss source said.