Three months to go before the general election, the first opinion poll to fully include the impact of Pieter Omtzigt’s decision to set up his own party shows the major upheaval ahead.

The I&O Research poll puts Omzight’s Nieuw Sociaal Contract party on 31 seats in the 150-seat parliament, making it the biggest grouping with some 21% of the vote.

Second in the poll, with 28 seats or 19% of the vote, is the PvdA/GroenLinks alliance led by former European commissioner Frans Timmermans. This is 11 more seats than the two parties currently have.

Third would be the VVD with 22 seats, or 15%, well down on the 34 seats the party won under Mark Rutte in 2021. Justice minister Dilan Yesilgöz has taken over as VVD leader following Rutte’s decision to step down.

The biggest loser from Omzigt’s decision to compete in the November vote is the CDA, which in the I&O poll would win just three seats, the same as fringe parties like the far-right FvD or minority rights group Denk. Omtzigt was a member of the CDA until 2021.

D66 would also be hit hard, with its support down from 24 seats to just seven. The pro-farmers BBB, which emerged as the biggest party after the provincial elections, would boost its MP total from one – party leader Caroline van der Plas – to 13, on a par with Geert Wilders’ far-right PVV.

Analysts point out that there is still much uncertainty and that Omtzigt has not yet outlined his position on controversial issues such as immigration, climate change and farming sector reform.

Nevertheless, his call for good governance and more trust between politicians and society would appear to have hit home, broadcaster NOS said in its analysis.

The poll also indicates that a coalition between the three biggest parties would be an option, but otherwise at least four parties would be needed to form a majority in the lower house of parliament.