Valdis Dombrovskis was speaking in an interview with AFP a day after EU President Donald Tusk said the only alternative to a hard Brexit -- which would see Britain pull out of the bloc's single market and impose tough immigration controls -- is "no Brexit".
"Well, from the European Commission point of view we are now emphasising that the ball now is in UK court. It's for UK government to decide on what model of cooperation with the EU they would envisage," said Dombrovskis, who oversees the euro and financial services at the EU's executive arm.
"But staying within the internal market comes with a number of conditions. If UK is ready to respect those conditions, certainly there's a possibility to discuss the so-called soft Brexit," he said, speaking in English.
"(What) President Tusk was probably referring to is more or less the statement which comes from UK government itself, which seems to be indicating rather towards a so-called hard Brexit."
Tusk is the head of the European Council, which groups the 28 EU leaders. He said in a speech yesterday: "I think it is useless to speculate about 'soft Brexit'.
"In my opinion, the only real alternative to a 'hard Brexit' is 'no Brexit'. Even if today hardly anyone believes in such a possibility," he said.
The pound has taken a battering as British leaders bicker over how to leave the European Union, with many fearing a hard Brexit would mean Britain withdrawing entirely from Europe's single market, and having to negotiate new trade arrangements, in order to impose strict immigration controls.
EU leaders have said Britain must accept free movement of people if it wants continued access to the single market and have warned the Brexit negotiations will be tough.
British Prime Minister Theresa May announced earlier this month her government will trigger those negotiations by the end of March, putting the country on course to leave the EU by early 2019.
Another EU commissioner, economics affairs chief Pierre Moscovici, took issue with Tusk's apparent hard line.
"I don't entirely agree," he said yesterday evening.
"Personally, I prefer a 'clean Brexit', that is that we continue to have friendly relations with the United Kingdom, a major power and a very major partner which will no longer be in the European Union but which will remain a European country.