The party’s leader, Władysław Kosiniak-Kamysz, on Saturday officially launched his grouping’s Polish Coalition election project.
Speaking in the central town of Piątek, Kosiniak-Kamysz said he aimed to "build bridges of understanding and not put up walls of hate.”
Despite weeks of talks, key opposition groups have failed to close ranks in the run-up to the country’s parliamentary elections.
Grzegorz Schetyna, leader of the Civic Platform (PO), Poland’s largest opposition party, announced on Thursday that his group was going into the parliamentary race without the Polish People's Party.
The two groupings jointly formed the Polish government for eight years until late 2015.
The Polish People's Party has its powerbase in conservative rural areas, and has been unable to come to an agreement with the more socially liberal Civic Platform.
Poland is due to hold parliamentary elections in October or November.
The governing conservative Law and Justice party won a landslide in elections in late 2015 and will be bidding for a second term in power.
Law and Justice on Saturday discussed its election programme with voters in Chełm, a city in eastern Poland.
Law and Justice leader Jarosław Kaczyński said he wanted Poles to have a decent standard of living and feel equal.
(pk)
Source: PAP