SOFIA (Reuters) - Bulgaria's centre-right GERB party has kept a tiny lead over its main political rival, the Socialists, ahead of an early parliamentary election on Sunday, an opinion poll by independent research centre Trend showed on Monday.
With as many as one in five voters undecided and a margin of just 1.9 percentage points between the leading candidates, the outcome is unpredictable, according to the poll of 1,004 people carried out between March 10 and 16.
The centre-right GERB party, whose government resigned in November after its candidate lost the presidential election to Socialist ally Rumen Radev, remains the most popular political party. But its support has dropped to 29.8 percent from the 32.7 percent of the vote it won the election with in 2014.
The support for the Socialists has been on the rise since Radev's victory and rose to 27.9 percent from 15.4 percent the party secured in 2014.
With neither of the two leading parties expected to win an outright majority, Bulgaria is likely to have a fragile coalition government that will struggle to push ahead with much needed reforms, analysts say.
Under Bulgaria's voting system, the seats are divided proportionally to the parties' share of the vote, as well as the parties that do reach parliament getting a proportion of the votes that went to parties that do not make the threshold.
For example, in 2014, GERB got 84 out of the 240 seats, and the Socialists 39. Both parties have said they will not form a grand coalition between them.
The poll showed three other parties are likely to win seats in the next parliament: the nationalist United Patriots coalition with 10.2 percent, the ethnic Turkish MRF party (8.7 percent) and the new populist Will party of businessman Veselin Mareshki (7.3 percent).
The Reformist Bloc, a grouping of small right-wing parties, who was a coalition partner in the last GERB-led government, would get 3.8 percent - below the 4 percent threshold for entering the parliament, the poll showed.
(Reporting by Tsvetelia Tsolova; Editing by Alison Williams)