Polish president Andrzej Duda will announce his decision on appointing a new prime minister after last month's election on Monday evening, an aide to the president said.

"After consultations and deep consideration, President Andrzej Duda made a decision regarding the so-called first step (of appointing a government). The decision is final ...," Marcin Mastalerek, head of Duda’s chancellery, wrote on Twitter, adding that Duda was planning a televised address later on Monday.

The Law and Justice (PiS) party which ruled in Poland for the last eight years won the Oct. 15 election but lost its absolute majority and is unlikely to find a coalition partner.

Three pro-European parties which have a majority in the parliament say they are ready to form a cabinet led by Civic Coalition leader Donald Tusk and have urged Duda not to delay his appointment. (Reporting by Anna Wlodarczak-Semczuk, editing by Ed Osmond)