(CNN)Mitt Romney warned Wednesday that Donald Trump's tax returns could contain a "bombshell" in a biting attack that hinted at clear signs of alarm in the Republican establishment at the billionaire's tightening grip on the party's presidential race.
"We have good reason to believe that there's a bombshell in Donald Trump's taxes," Romney told Fox News, and also called on the top anti-Trump contenders Sens. Ted Cruz and Marco Rubio to disclose their tax information as well.
"Either he's not anywhere near as wealthy as he says he is, or he hasn't been paying taxes we would expect him to pay or perhaps he hasn't been giving money to vets or to the disabled like he's been telling us he's been doing," Romney added.
The 2012 Republican nominee's broadside followed Trump's thumping victories in three of the first four GOP nominating contests, including in Nevada on Tuesday night, which have established the billionaire businessman as the party's undisputed front-runner.
It was also an attack steeped in irony, since Romney was on the receiving end of similar claims by then-Senate Majority Leader Harry Reid, when Democrats eviscerated him over his fortune and business record during the 2012 campaign. Reid zeroed in on his taxes, saying he hadn't paid any in a decade without offering any evidence to support the claim.
Romney, who decided against a third presidential run last year after initially considering jumping in to the race, uncorked his attack on Trump, ahead of next week's Super Tuesday contests that could further cement the billionaire's strong front-runner status in the GOP presidential race.
Trump's campaign did not respond to a CNN request for comment on the remarks, but the billionaire businessman tweeted after the interview that Romney is "playing tough guy."
"Mitt Romney,who totally blew an election that should have been won and whose tax returns made him look like a fool, is now playing tough guy," Trump tweeted.
"We have good reason to believe that there's a bombshell in Donald Trump's taxes," Romney told Fox News, and also called on the top anti-Trump contenders Sens. Ted Cruz and Marco Rubio to disclose their tax information as well.
"Either he's not anywhere near as wealthy as he says he is, or he hasn't been paying taxes we would expect him to pay or perhaps he hasn't been giving money to vets or to the disabled like he's been telling us he's been doing," Romney added.
The 2012 Republican nominee's broadside followed Trump's thumping victories in three of the first four GOP nominating contests, including in Nevada on Tuesday night, which have established the billionaire businessman as the party's undisputed front-runner.
It was also an attack steeped in irony, since Romney was on the receiving end of similar claims by then-Senate Majority Leader Harry Reid, when Democrats eviscerated him over his fortune and business record during the 2012 campaign. Reid zeroed in on his taxes, saying he hadn't paid any in a decade without offering any evidence to support the claim.
Romney, who decided against a third presidential run last year after initially considering jumping in to the race, uncorked his attack on Trump, ahead of next week's Super Tuesday contests that could further cement the billionaire's strong front-runner status in the GOP presidential race.
Trump's campaign did not respond to a CNN request for comment on the remarks, but the billionaire businessman tweeted after the interview that Romney is "playing tough guy."
"Mitt Romney,who totally blew an election that should have been won and whose tax returns made him look like a fool, is now playing tough guy," Trump tweeted.
