On the first day of Russia’s all-out invasion, President Volodymyr Zelensky of Ukraine and his main political opponent at home shook hands, setting aside their ferocious rivalry to focus on the enemy. The country’s typically raucous politics went largely dormant for the three years that followed.
Now, as peace talks led by the Trump administration have stirred prospects for a cease-fire and eventual elections, the political jockeying has returned.
Ukrainian politicians are maneuvering at home and reaching out behind the scenes to the Trump administration, which has made no secret of its disdain for Mr. Zelensky, despite his lionization on the world stage for standing up to Russia.
Petro O. Poroshenko, a former Ukrainian president and the leader of a rival party, says that the best way to smooth the peace talks is to bring opposition figures into the government.
Mr. Poroshenko had earlier floated the idea of overhauling Ukraine’s politics to form a national unity government, which could benefit his party. He revived the proposal after Mr. Zelensky’s contentious Oval Office meeting with President Trump in February and a call by a Republican senator for him to step down.
Mr. Zelensky has shown no interest in forming a coalition of ministers that would include opposition figures. Instead, his government has ratcheted up pressure on opponents by law enforcement and security agencies.
The mayor of Kyiv, Vitali Klitschko, has said Mr. Zelensky abused martial law powers to overrule the city council. In January, Ukraine’s national security council froze Mr. Poroshenko’s bank accounts while leveling no specific accusations.
“We don’t have any other option other than a coalition of national unity, a government of national unity,” Mr. Poroshenko said in an interview on Wednesday. “We should have unity in the Parliament and demonstrate unity in the country. And the results of this decision should be a stop to the war.”
Mr. Zelensky’s five-year term, which was set to expire last year, was extended under martial law. Elections are legally banned under martial law and impractical as long as Ukraine remains at war.
Nearly a month ago, Ukraine offered a monthlong, unconditional cease-fire that Russia has not accepted. A Trump administration envoy, Steve Witkoff, traveled to Russia on Friday, possibly in an effort to rekindle negotiations.
Mr. Poroshenko said that the talks could get a boost if Mr. Zelensky allowed political opponents to enter the government, given that Mr. Trump has called Mr. Zelensky a “dictator without elections.” That echoed criticism by the Russian president, Vladimir V. Putin, who has said he will not sign a peace settlement with Mr. Zelensky.
Mr. Poroshenko said he disagreed with Mr. Trump’s assessment of Mr. Zelensky as a dictator.
But with the prospect of a cease-fire and elections, Mr. Poroshenko has taken to more openly criticizing the president. The sanctions that the national security council placed on Mr. Poroshenko froze his bank accounts and could exclude him from future elections.
Mr. Poroshenko called the sanctions against him “disastrous, unconstitutional and extrajudicial.” If he were arrested, he said, he would then say that Ukraine is on a path to dictatorship.
The intense rivalry between the two Ukrainian leaders goes back years. Mr. Poroshenko led Ukraine from 2014 to 2019. After Mr. Zelensky soundly defeated him, the new government then questioned Mr. Poroshenko as a witness in a flurry of criminal cases that Mr. Poroshenko called politically motivated.
Even as tanks massed at the border before Russia invaded in 2022, the infighting continued in Ukraine: Prosecutors sought an arrest warrant for Mr. Poroshenko, though it was declined by a judge.
Mr. Poroshenko has a base of support in Ukrainian nationalist politics, particularly in western and central Ukraine, while Mr. Zelensky in the 2019 race won broad support across the country, including from Russian speakers in central and eastern Ukraine.
The two men met on the morning of Feb. 24, 2022, when Russia began its onslaught, to set aside their rivalry. Mr. Zelensky asked what he could do for Mr. Poroshenko. The former president said that he asked for 5,000 Kalashnikovs to arm his supporters against the Russians, and that Mr. Zelensky had provided the guns.
Mr. Poroshenko, 59, has little chance of winning a presidential election, polls show. He has consistently been in third place or lower, behind Mr. Zelensky and a former army commander, Gen. Valery Zaluzhny.
Political analysts say that Mr. Poroshenko may be angling for an electoral alliance with General Zaluzhny, who is serving as ambassador to Britain and is wildly popular in Ukraine. He has remained mostly silent about politics.
In the interview, Mr. Poroshenko said he had met with Mr. Zaluzhny in London, but he declined to disclose details of their talks. An aide to Mr. Poroshenko said he had accepted an autographed copy of the general’s biography, “Iron General.”
As Mr. Zelensky has negotiated with the Trump administration, Mr. Poroshenko has offered advice through intermediaries, he said.
“Trump can ask unexpected questions, I can say even impolite,” Mr. Poroshenko said.
At one meeting during the first Trump administration, Mr. Poroshenko said, Mr. Trump asked if he could get an honest answer to a question. Mr. Poroshenko said yes. Mr. Trump then leaned closer and asked, “‘Tell me, is Crimea Russian?’”
Mr. Poroshenko said he answered that Crimea, the peninsula that Russia seized in 2014, was Ukrainian, and asked what prompted the question. Mr. Trump then said that a Russian friend had told him that the peninsula should be Russian, Mr. Poroshenko said.
Mr. Poroshenko pursued a transactional foreign policy with the United States that partly paid off. That included purchases of coal from Pennsylvania that preserved some jobs in a swing state, even though Ukraine has abundant coal of its own.
Before the end of Mr. Trump’s first term, the administration offered a formal statement, known as the Crimea Declaration, that asserted as a matter of U.S. policy that Crimea was Ukrainian.
“He’s not easy,” Mr. Poroshenko said of Mr. Trump. “But now is the time of diplomacy.”
