The Liberal Movement says that the decision was taken during Monday's meeting of the Liberals' group in the council and the leaders of the party's Vilnius branch.
"In an effort to ensure faster and more efficient decisions in Vilnius, we are ceasing cooperation with the conservative group," it said in a press release.
Remigijus Šimašius, the mayor of Vilnius and the leader of the Liberal Movement, told BNS that they were in talks with the coalition of the Electoral Action of Poles (EAP) and the Russian Alliance, as well as with three members of the Order and Justice group, on a new coalition.
Simasius said that the decision had been "brewing for several months" as the Liberals had been in a minority position at the council due to resistance from the conservatives.
Valdas Benkunskas, the capital's vice-mayor and the head of the Homeland Union's group in the council, linked the Liberals' decision to corruption suspicions against their party.
"Apparently, our transparency requirements had caused a lot of inconvenience both to Simasius and to the Liberals for some time and it became even more inconvenient after formal suspicions were brought against the party," he said.
Renata Cytacka, the head of the EAP group in the council, did not comment on the Liberals' proposal to join the ruling majority.
Gediminas Rudžionis, the head of the Order and Justice group, told BNS that they were holding discussions, rather than formal talks, with the Liberals.
Thirty-one out of 51 members of the council are currently in the ruling majority, including 15 Liberals, eight Homeland Union councilors, four Social Democrats and four members of the Lithuania List party.
The council's members who are formally in the opposition include three Order and Justice councilors, Mark Adam Harold, a British national who has left the Liberal Movement's group, four councilors of the EAP and the Russian alliance, and six members of the Lithuanian Freedom Union led by Artūras Zuokas, a former mayor of Vilnius.