PODGORICA (Reuters) - The ruling party and opposition in Montenegro both claimed to be ahead in an election on Sunday for the largely ceremonial post of president, raising the prospect of a disputed result.

The ruling Democratic Party of Socialists (DPS) said its candidate, incumbent Filip Vujanovic, had won 53 percent of votes compared to 47 percent for opposition challenger Miodrag Lekic, based on 70 percent of votes counted.

Based on the same number of counted votes, the opposition Democratic Front said Lekic was on 50.5 percent and Vujanovic on 49.5 percent.

(Writing by Matt Robinson; Editing by Jason Webb)