Nikki Haley on Wednesday blasted Donald J. Trump for his backroom effort to twist delegate and primary rules in his favor, calling it “ironic” that a former president who fueled lies about his 2020 election loss was now trying to “bully” his way to the 2024 Republican nomination.

“It’s ironic for somebody who says that the election was stolen from him — he’s now showing that he’s going to bully his way through to try and win this election,” Ms. Haley said in an interview on Wednesday in Los Angeles.

She went on to say that the reason he was trying so hard to win the election was because he needed “to get off all these court issues that he’s dealing with.” “And I think Americans need to see this for what it is,” she said.

The rebuke is among the sharpest attacks Ms. Haley has aimed at Mr. Trump yet, as she has taken a more pugnacious approach toward her former boss, seeking to oust him from his perch atop the Republican nominating contest.

After perhaps her worst result in the contest so far — finishing second to “None of These Candidates” on Tuesday in Nevada’s primary, in which Mr. Trump was not competing — Ms. Haley has kept amping up her criticism of her rival — and her own party.

In Los Angeles on Wednesday evening, Ms. Haley opened with her now-standard attacks on Mr. Trump, slamming him for a “temper tantrum” in response to her second-place finish in New Hampshire, the campaign money he has spent on personal legal fees and his support from the Republican establishment.