Ted Cruz is accusing his Republican rival Donald Trump of exhibiting inconsistent conservatism, suggesting he is not prepared to be president.
Cruz accused the billionaire investor of becoming "rattled" and "dismayed" by the Texas senator's gains.
The war of words between Cruz and Trump intensified in recent days, with Trump continuing to question Cruz's eligibility to be on the ballot given his Canadian birth and for not disclosing loans he received from Citibank and Goldman Sachs for his 2012 senate race.
"Donald seems to be a little rattled," Cruz told reporters before a town hall in Washington, New Hampshire. "For whatever reason he is very, very dismayed. I guess as conservatives continue to unite behind our campaign, as his poll numbers continue to go down, he's a little testier."