TBILISI (Reuters) - Georgian Prime Minister Irakly Garibashvili resigned on Wednesday after two years in office in a surprise move less than a year before a parliamentary election.

Georgia's Prime Minister Irakly Garibashvili speaks during a news conference at his office in Tbilisi, Georgia, in this April 29, 2015 file photo. REUTERS/David Mdzinarishvili/Files

In a televised address to the nation, Garibashvili gave no specific reason for his decision which he said took immediate effect, but opposition politicians linked it to a decline in the popularity of the ruling Georgia Dream coalition which faces an election in October next year.

“I’ve made a decision today to resign from the post of prime minister ... I’m leaving this position today, but will remain a loyal soldier of my motherland,” Garibashvili said.

Garibashvili became the prime minister, the country’s most powerful position, in November 2013, when Bidzina Ivanishvili resigned and named his close ally as successor.

He served as an interior minister after Ivanishvili’s Georgian Dream coalition defeated former President Mikheil Saakashvili’s party in an election in October 2012 and took control both of the government and legislature.

“The interior minister’s position or prime minister’s post was never an end in itself for me. It was always an opportunity to serve my country and our people,” Garibashvili said.

But both observers and the opposition linked it to a sharp fall in support for Georgian Dream coalition down to 18 percent, according to a recent opinion poll.

“This reshuffle is linked to the upcoming parliamentary election. Members of the Georgian Dream coalition have seen a decline in their popularity rating and it would be difficult to start a pre-election marathon with the same premier,” an opposition politician Mamuka Katsitadze said.

The opposition blames Garibashvili’s government for mounting economic woes in the former Soviet republic of 3.7 million, which is the subject of geopolitical rivalry between Russia and the West.

It was not immediately clear who would replace Garibashvili, who will remain as an acting prime minister before a successor and a new cabinet is approved by parliament.

Foreign Minister Georgy Kvirikashvili is among candidates.