Ukraine rebuked the European Union's ambassador on Tuesday after he publicly criticised the government for creating a poor business climate and practising selective justice.
The ex-Soviet republic's ties with the EU have soured after a Kiev court sentenced former prime minister Yulia Tymoshenko, a fierce opponent of President Viktor Yanukovich, to seven years in prison last October on charges of abuse of office.
Brussels saw Tymoshenko's trial as politically motivated and has put off the signing of bilateral agreements on political association and free trade over the issue.
Further upsetting Kiev, ambassador Jose Manuel Pinto Teixeira criticised Ukraine for failing to improve its investment climate.
"Ukraine has, regrettably, a dismal record on the business climate," Teixeira told a meeting of government officials and businessmen.
"President Yanukovich's pledges, since he was elected, that vertical power was necessary to fight corruption and create an attractive business climate have regrettably produced no such results," he said.
Teixeira said in reality things were getting worse, there was less investment and the signing of a free trade deal between the EU and Ukraine had been "undermined" by the use of selective justice for political purposes.
Ukraine's foreign ministry was quick to respond, saying it was "surprised" by Teixeira's comments which it described as out of line with what is appropriate for diplomats, Interfax news agency reported.
"(Teixeira) was trying to participate in Ukrainian internal political processes and public discourse," the ministry was quoted as saying.
Ukraine ranked 152nd out of 183 economies included in the World Bank survey Doing Business 2012, after coming 149th in the previous annual survey. It has one of the worst tax systems in the world, according to the survey.