Georgia Prime Minister Irakli Garibasvili's government collapsed on Wednesday after a seventh minister quit his 20-member Georgian Dream coalition cabinet.

"I am resigning from my post," sports minister Levan Kipiani told a press conference. The move spells the end of the cabinet, as replacing one-third of its members automatically requires the entire cabinet to dissolve.

President Giorgi Margvelashvili has a week to formally nominate a new prime minister proposed by the parliamentary majority.

The prime minister-designate will then have two weeks to pick his team but will have to go back to parliament for a confidence vote.

As the legislature is dominated by the ruling Georgian Dream coalition led by the previous and now acting Prime Minister Garibashvili, it is expected to back his re-appointment.

Georgian Dream, assembled by former prime minister and billionaire tycoon Bidzina Ivanishvili, came to power in October 2012, ending a decade-long rule by staunchly pro-Western former president Mikheil Saakashvili and his UNM party.

Ivanishvili stepped down in November 2013 to make way for his longtime ally Garibashvili, but is widely believed to still call the shots.