Are you allowed to turn left in this situation?

In the photo, beyond the pedestrian crossing there is a police officer directing traffic. He is standing sideways to you, with his arm stretched out horizontally towards the line of oncoming vehicles standing on the left half of the roadway - for them this means no entry. For you, the sideways position means permission to enter the junction, so you may turn left. The answer is: yes.

The Regulation on road signs and signals states that a position in which the person directing traffic stands sideways to approaching vehicles means permission to enter the junction, and an arm stretched out horizontally, across the direction of travel of approaching vehicles, prohibits them from entering. The police officer's instructions take precedence over signals and signs. You turn left slowly, making sure that the stopped oncoming vehicles are really standing still.

Legal basis: § 108 para. 2 and 5 of the Regulation on road signs and signals; Art. 5 para. 2 of the Road Traffic Act (Prawo o ruchu drogowym)