KYIV, Ukraine (AP) — Ukraine’s parliament passed a controversial law Thursday that will govern how the country calls up new soldiers at a time when it needs to replenish depleted forces who are increasingly struggling to fend off Russia's advance.

The law was passed against a backdrop of an escalating Russian campaign that has devastated Ukraine’s energy infrastructure in recent weeks. Authorities said overnight missile and drone attacks completely destroyed the Trypilska thermal power plant, the largest power-generating facility in the capital region.

UKRAINE LOWERS MILITARY DRAFT AGE IN EFFORT TO BOLSTER TROOP NUMBERS IN WAR AGAINST RUSSIA

Two years after Russia’s full-scale invasion captured nearly a quarter of the country, the stakes could not be higher for Kyiv. After a string of victories in the first year of the war, fortunes have turned for the Ukrainian military, which is dug in, outgunned and outnumbered.

The country desperately needs more troops — and they need more ammunition — at a time when doubts about the supply of Western aid are increasing.

The mobilization law was first envisioned after Ukraine's summer counteroffensive failed to gain significant ground last year — and authorities realized the country was in for a longer fight.

In December, President Volodymyr Zelenskyy said Ukraine’s military wanted to mobilize up to 500,000 more troops. Army chief Oleksandr Syrskyi has since revised that figure down because soldiers can be rotated from the rear. But officials haven't said how many are needed.

The law — which was watered down from its original form — will make it easier to identify every draft-eligible man in the country, where many have dodged conscription by avoiding contact with authorities.

Under the law, men aged 18 to 60 will be required to carry documents showing they have registered with the military and present them when asked, according to Oksana Zabolotna, an analyst for the watchdog group Center for United Actions. Also, any man who applies for a state service at a consulate abroad will be registered for military service.

However, it remains unclear how the measure will ensure all draft-eligible men are registered. In that way, it "does not fulfill the main declared goal," she said.

The law also provides incentives to soldiers, such as cash bonuses or money toward buying a house or car — perks that Zabolotna said Ukraine can not afford.

It's not clear how many conscripts the law might lead to — and it's also unclear that Ukraine, with its ongoing ammunition shortages, has the ability to arm large numbers of new soldiers without a fresh injection of Western aid.

In total, 1 million Ukrainians are in uniform, including about 300,000 who are serving on front lines.

Lawmakers dragged their feet for months over the mobilization law, and it is expected to be unpopular. It comes about a week after Ukraine lowered the draft-eligible age for men from 27 to 25.

The law will become effective a month after Zelenskyy signs it — and it was not clear when he would. It took him months to sign the law reducing conscription age.

Earlier this month, Volodymyr Fesenko, an analyst at the Center for Applied Political Studies "Penta," said the law is crucial for Ukraine’s ability to keep up the fight against Russia, even though it is painful for Ukrainian society.

"A large part of the people do not want their loved ones to go to the front, but at the same time they want Ukraine to win," he said.

Thursday's vote came after the parliamentary defense committee removed a key provision from the bill that would rotate out troops who served 36 months of combat. Lawmaker Oleksii Honcharenko said in a Telegram post that he was shocked by the move.

The committee instructed the Defense Ministry to draft a bill on demobilization within several months, news reports cited ministry spokesperson Dmytro Lazutkin as saying.

Exhausted soldiers, on the front lines since Russia invaded in February 2022, have no means of rotating out for rest. But considering the scale and intensity of the war, devising a system of rest will prove difficult.

A soldier taken off the front lines because of injury told The Associated Press his comrades badly need respite.

"Of course, I want the boys to be released, at least after 36 months. There are no more thoughts, I want the boys to have some rest," said the soldier, who gave his name only as Kostyantyn for security reasons.

Ukraine already suffers from a lack of trained soldiers capable of fighting, and demobilizing soldiers on the front lines now would deprive Ukrainian forces of their most capable fighters.

Meanwhile, in what private energy operator DTEK described as one of the most powerful attacks this year, missiles and drones struck infrastructure and power facilities across several regions overnight.

Energy Minister Herman Halushchenko told reporters that it was a "large scale, enormous, missile attack that affected our energy sector very badly."

The Trypilska plant, which was the biggest energy supplier for the Kyiv, Cherkasy, and Zhytomyr regions, was completely knocked out and unable to supply electricity.

At least 10 of the strikes damaged energy infrastructure in Kharkiv, Ukraine's second-largest city. Foreign Minister Dmytro Kuleba said more than 200,000 people in the region were without power and Russia "is trying to destroy Kharkiv's infrastructure and leave the city in darkness."

Energy facilities were also hit in the Zaporizhzhia and Lviv regions.

Ukraine’s leaders have pleaded for more air defense systems — aid that has been slow in coming.

Four people were killed and five injured in an attack on the city of Mykolaiv on Thursday, said regional governor, Vitalii Kim. In the Odesa region, four people were killed and 14 injured in Russian missile strikes Wednesday evening, said governor Oleh Kiper.