Ukraine should secure the electoral system in its constitution, the head of the observer delegation of the Parliamentary Assembly of the Council of Europe (PACE), Andreas Gross, has said.

He noted at a press conference in Kyiv on Monday that the Venice Commission and the PACE had proposed that Ukraine secure a proportional electoral system with open lists.

"Perhaps, the authorities should walk this path, and this should be secured in a new constitution so as to not be able to change the electoral law before every election," Gross said.

"The legitimacy of the election results depends on the election process, but it also depends on proper legislation," he said.