Poland's main opposition leader has suggested that local election results were falsified and said he will ask his supporters to protest them at a rally Dec. 13.

Jarolslaw Kaczynski spoke Sunday, a day after Poland's electoral commission released the outcome of the Nov. 16 elections. There was a delay of days due to a computer malfunction.

The results showed Kaczynski's conservative Law and Justice party taking the second largest number of seats in regional assemblies after the ruling Civic Platform party. Exit polls had predicted Kaczynski's party as the winner.

The commission also said that 17.9 percent of the assembly votes were declared invalid. Officials say it was because the ballots were confusing.

Kaczynski said "we consider (the results) not true and unreliable, simply not to use the word 'falsified."