Donald Trump says Bernie Sanders should run as an independent

Senator Sanders said on his website he was an independent, rather than a democrat, as early as this month

Mr Trump insists the independent turned democratic candidate should return to his roots

Republican Donald Trump has said Bernie Sanders should run as an independent as he said he has “been treated terribly by the Democrats”.

Mr Trump’s advice comes as Mr Sanders's campaign has faced dwindling momentum after losing out in New York to Hillary Clinton.

On his website, the Vermont senator described himself as an independent until earlier this month, according to Politico.

Mr Sanders switched to the Democrats as otherwise he would not have been able to fully participate in the closed primary system and would not have received the same exposure. Other independents currently running for president include Jill Stein from the Green Party and Gary Johnson, the former governor of New Mexico, representing the Libertarian Party.

In an interview on Sunday with NBC, journalist Chuck Todd asked Mr Sanders whether the thought the Democratic party had been fair to him, and he shrugged.

“No. I think we have— look, we're taking on the establishment. That's pretty clear,” the senator replied. “The fact that we had debates that were scheduled — pretty clearly, to my mind, at a time when there would be minimal viewing audience, et cetera, et cetera. But you know, that's the way it is. We knew we were taking on the establishment. And here we are. So not complaining.”

“While we have a narrow path to victory, were going to fight for and through that path. We hope to win,” he added.

At the end of last year the head of the Democratic National Committee, Debbie Wasserman Schultz, said there was “nothing sinister” in the way the DNC scheduled six Democratic debates on television - versus 12 debates for the Republicans - and held them mostly at the weekend with less people likely to watch them.

Asked whether super delegates might switch from Ms Clinton to Mr Sanders after primaries in upcoming states like California, she told CNN on Tuesday that it “was not her job” to comment on that.

“Our process for developing the platform is going to be open and inclusive and expansive,” she said.

She added that Democrats will be making “enthusiastic choices” whereas Republicans are making a choice as to “who they dislike the least”.

Voters in five states will be casting their ballots today and Mr Trump and Ms Clinton are expected to sweep up aross Rhode Island, Maryland, Delaware, Pennsylvania and Connecticut, with more than 300 delegates up for grabs.

Senator Sanders' wife Jane, speaking to Wolf Blitzer on CNN on Tuesday, urged him and the broadcaster to focus less on “delegate math” and focus on the issues that “Americans care about”, like jobs and the economy.

“Hillary Clinton says there are more unite them [her and Sanders] than divide them, and they need to beat the Republicans,” she said. “But there are issues where they differ and they need to talk about that."