Speaking on Radio Zet, a private radio station, on Wednesday, Paulina Hennig-Kloska said the next prime minister should be "a representative of that party that won the biggest social mandate and at the same time has the ability to create a majority government."
She added that "that grouping is Civic Platform."
Asked whether Tusk should become prime minister, Hennig-Kloska said "that is always the decision of the leader of the party that is in a position to form a majority, in this case Tusk, so either him or a person designated by him."
Although the incumbent conservatives, Law and Justice, took the most votes in Sunday's elections, they lost their parliamentary majority.
This leaves three opposition groupings - Civic Coalition (KO), headed by PO; the Third Way, grouping Poland 2050 and the agrarian Polish People's Party (PSL), and the New Left – in the position to form a majority ruling coalition.
Hennig-Kloska went on to say the opposition had garnered almost 12 million votes.
"We have the most seats, we are declaring cooperation, and Law and Justice has no way to form the stable, majority government that Poland needs," she said. "So yes, PO should receive that mandate." (PAP)
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