SOFIA (Reuters) - Bulgaria's centre-right GERB party has slightly increased its lead over the leftist Socialist party, their main political rival, according to a survey published on Thursday, three days before a snap parliamentary election.
GERB, led by former prime minister Boiko Borisov, is vying with the Socialists to be the biggest party in the parliament, but with a tight margin of just 2.6 percent between them, the outcome of the Sunday vote is hard to predict.
Neither of the main contenders is expected to win an outright majority, meaning Bulgaria will most likely have another fragile and diverse coalition government that will struggle to push ahead with reforms to spur growth and combat corruption.
The survey by independent pollster Alpha Research showed GERB winning 31.7 percent of the vote on Sunday and the Socialists 29.1 percent. The poll was conducted on March 20-22 among 1,033 people.
Support for GERB edged up 0.2 percent from the poll carried out by Alpha Research last month. Backing for the Socialists fell 0.5 percent.
Borisov's minority government resigned last November after his candidate lost the presidential election to Russia-friendly, Socialist-backed Rumen Radev.
Radev appointed a caretaker government -- Bulgaria's sixth in four years -- after he took office in January.
Five or six parties are likely to win seats in the new parliament.
In the new poll, United Patriots, a nationalist alliance and likely kingmaker in the next assembly, saw its support drop to 8.9 percent from 10.8 percent a month earlier.
The popularity of ethnic-Turkish MRF edged up to 8.4 percent and support for the anti-establishment Will party, led by local businessman Veselin Mareshki, rose to 6.8 percent.
Support for the right-wing Reformist Bloc was 4.0 percent, equalling the barrier for entering the parliament, Alpha Research said.
(Reporting by Angel Krasimirov; Editing by Gareth Jones)