WARSAW (Reuters) - Poland's ruling Law and Justice (PiS) party said on Friday it planned legal changes to enhance democracy ahead of local elections next year but analysts said the measures aimed to boost the party's electoral prospects.

The party came third at the last local election in 2014 and its proposals, to be debated in parliament this month, would smooth a path for candidates supported by parties such as itself and make it harder for independent candidates backed by citizens committees.

Opinion polls show the nationalist party is supported by 37 percent of the electorate and many voters say its policies fight inequality. The European Union, however, says that its policies undermine democracy and the rule of law.

"We will introduce two terms for mayors and presidents starting from 2018. (We also plan) to replace majority electoral law with a proportional system," PiS deputy Lukasz Schreiber told a news briefing.

Critics say many voters appreciate the PiS welfare program and so turn a blind eye to changes it has made to the judiciary and media aimed at cementing its rule.

The party wants changes including scrapping single-member constituencies in which the candidate with the most votes wins, party representatives told reporters in parliament on Friday.

PiS leader Jaroslaw Kaczynski says the present system is undemocratic and creates scope for abuses. Kaczynski has no formal post in the government but is seen as the ruler of the former communist country of 38 million people.

On Friday, state television showed a quote from Kaczynski from last month in which he said the system of single-member constituencies was undemocratic because it led to entrenched local leaders all-but certain to win re-election.

"There are some places in Poland where we (PiS) received 40 percent of votes (in local elections) but we have nothing or almost nothing. It is undemocratic. It creates a danger of abuses ... and one needs to eliminate this," he said.

Local elections are expected in late 2018.

Many town leaders elected in 2014 had the support of local committees rather than established parties. The leaders are called presidents in cities and mayors in towns.

The biggest opposition party Civic Platform, which is centrist, came second in that election while the PiS was third.

"Initial information suggests that the PiS project favors big parties as it scraps single-member constituencies. This looks like politicizing the local election," said Anna Materska-Sosnowska, a political analyst at Warsaw University.

Critics say the party has taken control over state companies, institutions, media, and the judiciary in order to strengthen its power and improve party's chances in future elections.

(Reporting by Marcin Goclowski and Pawel Sobczak; Editing by Matthew Mpoke Bigg)