Bernie Sanders pushed back this week against Republican presidential nominee Donald Trump's efforts to woo supporters of his Democratic primary bid, penning an Op-Ed piece that outlines reasons voters should say "No" to the businessman.

The Vermont senator, who waged a tough primary fight against Hillary Clinton, highlighted four reasons why he's backing his former opponent over Trump in a post published on Medium.com Monday.

The post came just days after the release of reportedly hacked audio of Clinton questioning Sanders' so-called "political revolution" during a February fundraiser -- comments which Trump's campaign seized on in its continued efforts to court backers of the senator.

Contending that Clinton is "far and away, the superior candidate in this election," Sanders blasted Trump's economic and tax plans, saying they would benefit only the wealthiest Americans.

"At a time of massive income and wealth inequality, we must not elect a president who wants to resurrect the failed trickle-down economics of the past. When the very rich are becoming much richer and there has been a 10-fold increase in the number of billionaires since the year 2000, it is economic insanity to propose, as Trump has, hundreds of billions in tax breaks to the top 1 percent," he wrote.

Sanders also criticized the GOP nominee's stance on climate change and accused him of making "bigotry the cornerstone of his campaign."

Further, the Vermont senator argued that the businessman "has taken lies and distortions to a whole new level," adding that former GOP nominee Mitt Romney was right in calling Trump a "fraud" and a "phony."

Clinton, by contrast, supports raising the minimum wage, pay equity and making public colleges tuition free for all families earning less than $125,000 annually, as well as backs efforts to combat climate change, he said.

"For those reasons and many more, Donald Trump must not become the next president of the United States," he wrote. "On November 8, the choice is clear. Hillary Clinton for president."

Earlier this week, Trump made his own case to Sanders' supporters following the release of audio in which Clinton took slight jabs at her primary opponent.

"Crooked H is nasty to Sanders supporters behind closed doors. Owned by Wall St and Politicians, HRC is not with you," he tweeted on Saturday.

Crooked H is nasty to Sanders supporters behind closed doors. Owned by Wall St and Politicians, HRC is not with you. https://t.co/WN1lyCDXla — Donald J. Trump (@realDonaldTrump) October 1, 2016

Sanders, who campaigned alongside Clinton in New Hampshire last week, will join the former secretary of state for a joint rally in Maine on Friday.