Poland will make a decision about when to join ERM2 at the end of May, Finance Ministry official Marek Rozkru has said.

He described the government's current aim of joining the excahnge rate mechanism - a precursor to joining the eurozone - on July 1 as "ambitious but realistic."

He added that the current volatility of the Polish currency was too high to "guarantee security" in ERM. Erm means the zloty will be pegged to the euro and allowed to move only within a narrow band before the single currency is introduced.