Political parties expressed their sadness over the killing of prominent lawyer Mihalis Zafiropoulos on Thursday and called for the prompt arrest of those responsible. Zafiropoulos, aged 52, was shot and killed in his office by unknown individuals.

"Authorities must move quickly to solve the case of the brutal murder. We express our warm condolences to the family and associates of Mihalis Zafiropoulos," SYRIZA said.

New Democracy (ND) leader Kyriakos Mitsotakis expressed his abhorrence, saying he was a great friend. "I express by abhorrence over M. Zafiropoulos's brutal assassination. [He was a] Worthy lawyer, distinguished member of ND and a very good friend," he said in a tweet.

ND also expressed its sadness in a separate press release, noting the contribution of his father, former New Democracy MP Nontas Zafiropoulos. Mitsotakis cancelled the presentation of the party's new communications staff which was scheduled for Friday.

PASOK President Fofi Gennimata condemned the "brutal and cowardly murder" Zafiropoulos, saying it creates "abhorrence and deep sadness".

"I express my sincere condolences to his family and his family," she said.

On his side, Potami leader Stavros Theodorakis said he's saddened and worried about the "mafia-style murder of Zafiropoulos in the heart of Athens."

"Greece will not be left at the mercy of gangs,? he added.