OREANDA-NEWS  Ukraine's top opposition politician was released as part of a large-scale prisoner exchange with Russia, President Vladimir Zelensky announced on Thursday morning.

Viktor Medvedchuk had been imprisoned last year over treason charges his supporters claimed were politically motivated. The move came just after his party passed out Zelensky's ruling 'Servant of the People' in opinion polling.

A total of 215 soldiers and other service personnel were returned to Ukraine, the president added in a video address.

Zelensky stated that during the swap Kiev managed to return 188 fighters who were captured when Russian and Donbass troops seized the Azov Sea port of Mariupol in May. Among them are 108 members of the Azov Battalion, whose ranks include fighters with openly nationalist and neo-Nazi views.

“This is clearly a victory for our state, for our entire society,” Zelensky said. “We will definitely do everything to save everyone who is in Russian captivity.” 

Zelensky explained that the swap was negotiated in two stages. During the first, Ukraine traded Medvedchuk, whom Zelensky described as a “fan of Russia,” for the release of 200 fighters.

According to the Ukrainian president, Kiev later agreed to swap 55 people, including those who “betrayed” the country, for five commanders, including Azov commander Denis Prokopenko.

Zelensky added that Turkey helped to facilitate the negotiations. He said that President Recep Tayyip Ergodan had agreed that the five captured Ukrainian commanders would remain “under the personal protection of the Turkish president until the end of the war.” 

Erdogan described the upcoming exchange to PBS NewsHour on Monday as “a significant step.”

Moscow has not yet commented on the matter. Russia and Ukraine have conducted several prisoner swaps since open hostilities broke out.

The news of a major exchange comes after British Prime Minister Liz Truss confirmed on Wednesday night that five captured UK nationals, who were fighting alongside Ukrainian troops, had also been released. Two of them were previously convicted of war crimes by a court in the Donetsk Peoples’ Republic and sentenced to death.

Zelensky thanked Saudi Arabia for its help in returning 10 foreign nationals that were captured while fighting alongside the Ukrainian Army.