Sen. Ben Sasse, R-Neb., who has staked out a leading role as a Donald Trump critic, and Ohio Gov. John Kasich are the top prospects being courted to run as an independent candidate against Trump and Hillary Clinton.

Mitt Romney, the Republican's 2012 presidential nominee, is among a group of Republicans actively leading the independent candidate effort, according to a Washington Post report. Sources tell the Post Romney has personally reached out to both men in recent days.

Earlier options for an independent candidate included former Sen. Tom Coburn, R-Okla., and retired Marine Corps. Gen. James N. Mattis. Former Secretary of State Condoleezza Rice and retired Army Gen. Stanley A. McChrystal were also listed as possible candidates.

"The governor is not entertaining nor will he run as an independent," Kasich's spokesman Chris Schrimpf said. Kasich shut down his quest for the Republican nomination earlier this month after Trump won the Indiana primary.

Read more on WashingtonExaminer.com