"The Communist faction will propose abolishing the post of president, which does not correspond to the nation's centuries-long democratic traditions and has hampered state development," leader Petro Symonenko said Friday.
Symonenko said the presidential form of government had proved to be totally ineffective and even harmful in the recent period of Ukraine's modern history. He said a parliamentary republic was the most appropriate option for Ukraine.
"Political reform gave people's deputies the right to form governments, define policies and control government activities with regard to popular vote results," Symonenko said.
Communists have 21 seats in the 450-seat Supreme Rada and are part of the anti-crisis coalition formed in June, along with the Party of Regions, the largest grouping in parliament, and the Socialist Party.
They all signed the national unity pact, proposed by President Viktor Yushchenko, with Our Ukraine group, ending four months of political crisis that followed the March parliamentary elections in the country.
The pro-presidential Our Ukraine faction has been engaged in consultations with the three parties on the possibility of expanding the coalition.
But friction has persisted between the political forces as Prime Minister Viktor Yanukovych, who is also the leader of pro-Russia Party of Regions, moved to downplay Ukraine's plans to join NATO in Brussels earlier this week, thereby violating the national unity pact.
Western-leaning President Yushchenko has made NATO membership a priority since coming to power following a popular uprising in 2004, but he has met with strong opposition on the issue from pro-Russian political forces and the population at large.