Warsaw’s liberal mayor and his insurgent populist challenger are locked in a dead heat as they fight for the presidency of Poland, exit polls projected after Sunday’s head-to-head vote, leaving the country tilting between two wildly different political futures.

A vote seen as a test of the power of populist nationalism in Europe was too close to call, with exit polls putting the two contenders neck and neck.

The knife-edge result would be another rejection of the populist right.