"We need to acknowledge that over many, many years we've been over-promising and under delivering," Frans Timmermans, first vice president of the European Commission, told Christiane Amanpour
"I believe many people -- especially small- and medium-sized enterprises across the European Union -- are disenchanted with Europe because we haven't delivered the goods."
With or without the United Kingdom, he said, the EU's governing institutions should try to under promise and over deliver.
European leaders have stayed relatively mum on Britain's June 23 referendum, which -- if successful -- would irrevocably change the EU.
Polls are incredibly tight. If UK citizens voted to leave, British leaders would have two contentious years to negotiate the terms of divorce.
"I think we've been doing, for many, many years, a lot of legislation that was nice to have without proving that we really needed to have it," Timmermans said.
"We're concentrating on the main issues now -- migration, refugees, security, creating an internal market that works, the digital single market, creating an energy union."
To that end, the European Commission has released a plan it hopes will turn into a comprehensive way to tackle the overwhelming influx of refugees and economic migrants to its southern member states.
A large component of the plan is a deal, struck with Turkey, to stem the flow of people across the Aegean Sea to Greece.
That deal trades the burden of sharing refugees with Turkey for an acceleration of a program that would grant visa-free travel to Europe for Turks -- something the Turkish government has long sought.
The agreement has come under severe criticism from people who accuse European leaders of being blackmailed by the government in Ankara that appears increasingly authoritarian, especially in its treatment of dissidents and the media.
Timmermans challenged critics "to give me a better idea."
"Simply standing back to back, not talking to each other, just blaming each other -- what did that do for human rights in Turkey? What did that do for the freedom of the press in Turkey? Nothing whatsoever," he said.
"Had we not entered into an agreement with Turkey, and with the Balkan borders being closed, we would have condemned Greece to become one huge refugee center for hundreds of thousands of people crossing the Aegean Sea -- many of whom would die crossing the sea, other who would live in terrible conditions in Greece.
"Isolating Turkey is not the right answer."