Bernie Sanders, the independent Vermont senator who is running for the Democratic presidential nomination on 2016, on Sunday denied that he would be a “spoiler” for the electoral chances of the establishment favourite and said: “Maybe I shouldn’t say this: I like Hillary Clinton.”

Sanders also asked if the media would “allow us to have a serious debate”, and said: “Or is the only way you get media attention by ripping apart somebody else?”

Clinton is the clear frontrunner for the Democratic nomination to succeed Barack Obama in the White House, polling well over 50% ahead of Sanders, the only other declared candidate, and potential contenders such as former Maryland governor Martin O’Malley and the former Virginia senator Jim Webb.

Sanders, a self-declared “democratic socialist” who has repeatedly championed social reform on a Scandinavian model and attacked the influence and behaviour of the wealthiest sections of society, appeared on CNN. He was asked how he differed from Clinton on income inequality, a key issue in both campaigns so far.

“It’s one thing to talk about it, it’s one thing to act on it,” Sanders said. “I have been helping to lead the fight for the American middle class for the last 25 or 30 years … in the Senate I am leading the effort to raise the minimum wage up to $15 an hour so that people who work 40 hours a week will not be living in poverty.

“We have presented legislation that will say to the wealthiest people and the largest corporations, ‘You know what? You can’t continue to avoid paying your fair share of taxes.”

Sanders was asked if he would have a “civil debate” with Clinton in the months to come, given her status as a member of the political establishment he said he did not represent, and given that she has been widely criticised on matters regarding her wealth. On Friday she and her husband, former president Bill Clinton, said they had earned more than $25m in speaking fees since January 2014.

“I’ve never run a negative political ad in my life,” Sanders said. “…I believe in serious debates on serious issues. I’ve known Hillary Clinton for 25 years. Maybe I shouldn’t say this: I like Hillary Clinton. I respect Hillary Clinton.

“Will the media, among others, allow us to have a civil debate on civil issues? Or is the only way you get media attention by ripping apart somebody else?”

Sanders did say Clinton should indicate her position on the proposed Trans Pacific Partnership trade deal which is dividing Democrats and forcing Obama to depend on Republican support in Congress.

“You’re either for or you’re against it,” he said. “There’s no fence-sitting on this one.”

Sanders is against the agreement, which he says would be “disastrous” for middle-class American jobs.

Clinton has not committed herself. Last month her campaign chief, John Podesta, was quoted as having told donors: “Can you make it go away?”