In this situation, can you enter the intersection in order to go straight?

At the junction there is a police officer directing traffic, standing side-on to you, and the traffic lights show green. Standing side-on to approaching vehicles means permission to enter the junction, so you can go straight on. If the police officer stood facing you or with their back to you, it would mean a ban on entering - regardless of the colour of the light.

The Regulation on road signs and signals says that the person directing traffic gives signals with body position and arm movements: standing side-on means permission to enter, and standing face-on or with the back to the vehicles means a ban. The Road Traffic Act adds that the instructions of the person directing traffic take precedence over light signals and signs. As you enter, watch the police officer - a raised arm announces a change of signal.

Legal basis: § 108 para. 1-3 of the Regulation on road signs and signals; Art. 5 para. 1 and 2 of the Road Traffic Act (Prawo o ruchu drogowym)