Countries on Europe's periphery – Portugal, Ireland, Italy, Greece and Spain – have been hard hit by the euro zone's debt crisis. Efforts to cut their budget deficits have led to tough austerity regimes, which have in turn hit growth prospects. Unemployment in the euro zone remained stuck its record high of 12.1 percent in June, official figures showed at the end of last month.
Loynes said that these structural problems had the potential to cause big problems for the rest of the euro zone..
"The peripheral economies remain a very long way from the rates of expansion required to address their deep-seated problems of mass unemployment and cripplingly high debt," he said. "Market concerns about these countries – and whether they could default, or leave the euro zone - could flow back again at some points, which would hit growth."
The chief European economist at IHS Global Insight, Howard Archer, agreed that the euro zone's recovery would be limited by "serious headwinds" from the periphery.
"Notably including still restrictive fiscal policies (even though countries are being given more flexibility on this), ongoing tight credit conditions amid still significant banking sector problems, very high (and still likely further to rise unemployment) and muted consumer purchasing power," he said.
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The euro zone's 0.3 percent euro zone GDP figure "overstated the region's economic health," Archer added, with any further growth likely to be limited.
Societe Generale economist Anatoli Annenkov agreed there were pressures on continued GDP growth in the euro zone. "While [the data are] positive, especially for confidence, we expect continued headwinds in the autumns stemming from financial fragmentation and struggles in delivering fiscal consolidation," he said.
He stressed that temporary factors, such as low temperatures which had boosted energy consumption, were unlikely to be present in the third quarter, and that the euro zone's GDP data would likely be revised – possibly lower.
Wednesday's preliminary estimate of euro zone GDP growth was driven by a pickup in economic growth across both Germany and France. Germany cemented its position as Europe's powerhouse, with a 0.7 percent surge in growth, while France jumped out of recession, posting expansion of 0.5 percent. Portugal's GDP also surprised on the upside, with economic growth of 1.1 percent in the second quarter.