The fate of the European Union’s Lisbon treaty will be in question again this week as political instability in the Czech Republic raises the prospect that the charter will not come into effect as planned on January 1 2010.

According to EU officials, the biggest fear of policymakers in Brussels is less that Irish voters will reject the treaty for a second time in a referendum on October 2 than that Vaclav Klaus, the anti-Lisbon Czech president, will exploit the domestic political situation to delay signing the document.