Britain should be allowed to delay its official Brexit departure date again so it can think carefully about its future, the EU's competition chief told CNBC.

"I don't see a risk in prolonging the departure (from the European Union)," Margrethe Vestager, the European Commissioner for Competition said Tuesday in an exclusive interview in Brussels.

"If you need to reconsider how the Brexit referendum should be respected; what would be the preferred U.K. choices, I don't see a risk in a prolongation … I think it's never a risk to think twice and to sleep on it then sometimes you wake up and you reconsider," she said.

The process to take the U.K. officially out of the European Union began two years ago, but has yet to be finalized. U.K. parliamentarians have so far rejected the deal that Prime Minister Theresa May negotiated with the EU three times.

Michel Barnier, the EU's chief Brexit negotiator, said Tuesday that it's more and more likely by the day that the U.K. will leave in an abrupt way without any transition phase.

"This is a serious crisis and no-one can be pleased with what is happening in the U.K. currently," he said at an event in Brussels.

At the moment, the U.K. is scheduled to leave the EU on April 12 and will be the first country to leave the bloc. However, Prime Minister Theresa May said Tuesday she is going to ask for another short extension, until May 22, as she seeks to find a way forward with the country's opposition party.