The Minister for Finance, Mr McCreevy, has blamed national governments for failing to remove remaining barriers to trade within the European Union.
In a written response to questions from the European Parliament, Mr McCreevy, who will become Internal Market Commissioner in November, said that most policymakers agreed on what had to be done to complete the internal market.
"What remains is to do it. It is the member-states who need to change their attitudes and behaviour most.
"We would be a long way towards achieving our goals if they implemented agreed measures on time and then applied them effectively; if they refrained from adopting national measures which damage the internal market; if they informed their citizens and business better about internal market opportunities; and if they co-operated more among themselves to exchange information and solve problems pragmatically," he said.
Mr McCreevy said that the EU needed to rediscover what a valuable asset the internal market is and to demonstrate that it could be combined with strong consumer, social and environmental protection. He said that, despite efforts to improve communication with citizens, the EU remained "remote and obscure" for most people.
"You only have to look at opinion polls or the turn-out in the June elections. We clearly have to do something more or differently to get our message across," he said.
Mr McCreevy identified as one of his main ambitions the removal of a perceived conflict between removing trade barriers on one hand and consumer protection on the other.
He said he would work closely with the commissioner responsible for consumer protection to ensure that his actions improved competition and the free movement of goods and services while protecting consumers' interests.
"Having an internal market which offers quality and choice at competitive prices is good policy. Giving consumers confidence that they can buy safe products right across the EU is good policy.
"What is bad policy is allowing member-states to use consumer protection in such a way as to fragment the internal market, as this will result in denying consumers significant benefits in terms of healthy competition and choice," he said.
Mr McCreevy added that the removal of obstacles to cross-border trade in services was essential if the European Union was to realise its economic growth potential.
"A wide range of legal and administrative barriers inhibit direct cross-border trade in services and make it unnecessarily difficult, if not impossible, to set up permanent establishment in other member-states to operate as a true European service provider.
"These barriers include, but are not limited to, onerous authorisation and licensing regimes, discriminatory conditions applying to certain activities and outright bans.
"As a result, there has been little market integration and not enough competition, with the result that productivity growth has been held back," he said.
The European Parliament's Internal Market Committee will question Mr McCreevy in person next month. The European Parliament must approve the entire Commission before it takes office on November 1st.
