Leader of the main opposition conservative Law and Justice (PiS) Jaroslaw Kaczynski said on Thursday that a motion calling for a constructive vote of no-confidence in the government of Donald Tusk would be submitted to the Sejm this week, most likely on Friday.

In line with Poland's constitution, a motion for a constructive no-confidence vote requires presenting a candidate for the post of Prime Minister. The motion has to be signed by at least 46 MPs.

PiS had earlier proposed a non-partisan candidate – an independent sociology professor Piotr Glinski to replace Tusk and form an extra-party cabinet. Glinski will start consultations with parliamentary parties on the composition of his cabinet shortly after PiS tables its no-confidence motion.

PiS must secure an absolute majority of 231 votes and the sympathy of the left-wing opposition and a rightist splinter party Solidary Poland which is sporting a PM candidate of its own.