Poland’s largest opposition party fractured on July 24 after former Prime Minister Mateusz Morawiecki and his loyalists rejected an ultimatum from Law and Justice (PiS) chairman, Jarosław Kaczyński, to abandon their in-party Rozwój Plus (Development Plus) association.

“Thirty-something” MPs had thereby resigned from PiS and party authorities would formally acknowledge the fact on July 28, Kaczyński tld a press conference at PiS's headquarters in Warsaw.

The dissenters said they had not resigned and were instead being expelled due to an “intrigue”.

The former PM argued that his “two lungs” strategy would let PiS retain its core conservative voters while Rozwój Plus would court younger people, entrepreneurs and centre-right voters.

Morawiecki said his camp comprised 40 MPs (including three formally unassociated with any party), one senator and three MEPs. The departure of the MPs will now make PiS's parliamentary caucus only the second-biggest in the lower house, behing Prime Minister Donald Tusk's Civic Coalition.

Morawiecki launched Rozwój Plus in April after Kaczyński’s choice of former education minister Przemysław Czarnek as PiS’s candidate for prime minister signalled a push to recover voters lost to the hard right.

Kaczyński’s camp viewed the association as a rival power base and demanded that PiS parliamentarians leave outside political associations by midnight on July 23.

The split gives Morawiecki a group, but its electoral base will only be affirmed over time.

A potential Rozwój Plus party won 6.2%, just above Poland’s 5% parliamentary threshold, while PiS fell from 23% to 17.7%, a poll by Opinia24 pollster for TVN and TVN24 showed on July 21, before the split was confirmed.

A separate survey put Morawiecki’s party on 6.9%, an IBRiS poll for Wirtualna Polska, a news website, showed on July 20.

Broader polling has consistently placed Tusk’s Civic Coalition first but suggested his four-party government would lose power, falling some 30 seats of a majority in the parliament.

In theory, that could mean a joint government by PiS, Morawiecki's grouping and the two far-right parties, the Confederation and the Confederation of the Polish Crown.

But a pivot by Tusk to ditch his current coalition partners to work with Morawiecki or even with the Confederation cannot be ruled out.

The next election is due in the autumn of 2027.

Close to 60% of Poles expect the governing coalition to lose the next election, while only a fifth think it would retain power, an IBRiS poll for Wirtualna Polska showed on July 26.