Frankfurt - The European Central Bank called Poland's plan to enter the eurozone by 2012, "ambitious, but realistic," said Polish Prime Minister Donald Tusk after talks with the bank's leadership in Frankfurt, Germany on Wednesday.

Tusk said the recent world economic crisis has made the currency swap more difficult for Poland, but not impossible.

"Poland's situation - like our discussion partners emphasized - isn't bad compared to many other countries in the region," Tusk said. "Both sides didn't deny that the context is harder than it could have seemed to us two or three months ago."

Tusk added he will work to sway Poland's euro-sceptic opposition party, whose support is needed to change the constitution. Currently the constitution gives the National Bank sole power to distribute money.

"We will do everything in Poland to get a consensus," Tusk said, "And we realize without a consensus, the project will get delayed."

Tusk said the bank agreed that the constitution should be changed before Poland enters the exchange rate mechanism (ERM-2), a precursor to euro membership.

The Polish government recently accepted a road map to enter the eurozone by 2012, while Tusk noted that he must still overcome scepticism from the opposition.

Tusk failed to win over Jaroslaw Kaczynski, head of the opposition Law and Justice party, at a recent meeting in Warsaw, but said he will continue talks.

Tusk surprised many analysts when he recently announced his government would work to adopt the euro by 2012. He has also said the global financial crisis gives Poland stronger reasons to join the 15- member area. (dpa)