President Grabar Kitarović said: "The time has come to leave the ashes of the past behind." | ELVIS BARUKCIC/AFP/Getty Images Croatians vote in November with ruling SDP behind in polls PM Milanović took his country into the EU but it remains poor — and he’s behind in the polls.

Croatia will hold a general election on November 8, the first vote since the country entered the European Union in 2013, with the ruling Social Democrats (SDP) trailing behind the center-right opposition Croatian Democrats (HDZ) in recent opinion polls.

SDP Prime Minister Zoran Milanović took Croatia into the EU following a 2012 referendum in which 66.25 percent voted in favor of membership. However, accession has not brought the immediate benefits many Croats had hoped for and their country remains one of the poorest in Europe.

Although the economy is now recovering from a six-year downturn, Milanović’s government has been blamed for a lack of reform in the public sector and a failing investment climate.

Ahead of the elections announced by President Kolinda Grabar Kitarović, the opposition HDZ — which has been in government for 17 of the 25 years of Croatian independence — has 30 percent support in polls, followed by the SDP on 25 percent.

The brief election campaign risks being dominated by the migrant crisis, which has seen almost 120,000 refugees enter Croatia across its eastern border since September. Milanović criticized neighboring Serbia for not sending migrants towards Hungary and Romania, triggering a border row between the two former members of Yugoslavia.

President Grabar Kitarović, who took office in January and belongs to the HDZ, appealed for a serious campaign, calling on the candidates not to “turn this festival of democracy into a carnival of democracy.”

Milanović, the 45-year-old prime minister, has governed at the head of a center-left coalition between his SDP, the Croatian People's Party (HNS) and the Istrian Democratic Assembly (IDS) since 2011.

Watch Grabar Kitarović's election announcement: