Just this summer, Ireland and its creditors from the European Union and the International Monetary Fund seemed to agree: When its bailout program runs out this winter, Dublin should jump back into the wild water of financial markets with a life vest—a precautionary credit line from the euro-zone rescue fund—just in case.

But now the Irish government looks more likely to take the plunge without one. Euro-zone finance ministers could give it the go-ahead as early as Thursday, according to European officials, which would make Ireland the first country to exit a full-blown euro-zone bailout.

Spain, which received money in late 2012 only for its banks, has already said that it doesn't want its aid plan to be extended.

If the Irish decide they want what is being termed a "clean exit," then that decision can be made at the upcoming ministerial meeting in Brussels, a senior EU official said Tuesday.

Members of the Irish government, including Finance Minister Michael Noonan and his deputy Brian Hayes, note they have until Dec. 15 to make up their minds. But when Mr. Hayes briefed reporters in Brussels this week, his arguments tilted firmly to one side.