During municipal elections of 1998 KPEiR, allied with Democratic Left Alliance (SLD), Polish People's Party (PSL) and Labor Union (UP) won some seats.

[8][9] In the 1995 Polish presidential election, the party supported Tadeusz Zieliński (ombudsman, Union of Labour candidate).

[9] In the 1998 Polish local elections, the KPEiR party entered into an electoral agreement with the PSL and the Labour Union, under the name Przymierze Społeczne.

As a result, KPEiR ran on its own in the 2002 Polish local elections and won 127,299 votes (or 1.14% of overall support), failing to win seats in the sejmiki voivodship.

In the 2006-2010 term, on the basis of an agreement with PO, Krystyna Pajura, an activist from the KPEiR, sat on the Pomorskie Voivodeship board (she was dismissed in January 2010 after the change of marshal;[10] at the end of this term a councillor of the Pomeranian Voivodeship Sejmik elected from the Self-Defence of the Republic of Poland list became affiliated with the party.

In the 2009 European Parliament election in Poland, KPEiR candidates ran on the lists of the SLD-UP coalition, but did not win any of the 7 MEP seats that went to the committee.

In the 2010 Polish local elections, the party fielded lists to the Sejmiks in 13 provinces, receiving a total of 1.82% of the vote, which was the fifth highest result nationally.

One of the vice-presidents of the KPEiR, Sławomir Słomka, in turn became a candidate of the Polska Jest Najważniejsza party.

On 19 April 2012, party leader Tomasz Mamiński resigned from his position and his duties were taken over by Tadeusz Staniewski.

On 31 May, Tadeusz Staniewski was replaced as acting chairman by Wojciech Kornowski, and elections for the new authorities were scheduled for 20 September.

In 2014, the KPEiR signed an agreement to work closely with the Alliance of the Democratic Left, but its activists were not on the electoral lists for the European Parliament.

In the 2014 Polish local elections KPEiR was, together with the Democratic Left Alliance and the Union of Labour, a member of the SLD Lewica Razem coalition, for which it fielded candidates for councillors at various levels.

In the 2015 Polish parliamentary election, several KPEiR activists ran for the Sejm from the United Left lists, which did not win seats.

[14] KPEiR claims to represent not only the interests of pensioners, but every weak and disadvantaged group of Polish society at large.