European Union leaders will sift through the wreckage of the Lisbon treaty on Monday in search of something to salvage from the bitter blow of Ireland’s rejection of the agreement.

Nicolas Sarkozy, France’s president, will visit Prague in an attempt to stiffen the Czech government’s resolve to ratify the treaty after Vaclav Klaus, the Czech president, dropped a bombshell by declaring that the Irish referendum last week had buried it for good.