ANKARA, Turkey -- Turkey's president is suing the country's opposition leader for slander for allegedly claiming before a national election that bathrooms in his 1,150-room palace had gold-plated seats, his lawyer said Tuesday.

Lawyer Muammer Cemaloglu told the state-run Anadolu Agency on Tuesday that President Recep Tayyip Erdogan was seeking 100,000 Turkish Lira ($37,000) in compensation from main opposition leader Kemal Kilicdaroglu.

Erdogan had earlier invited Kilicdaroglu to inspect the $620 million palace, saying he would resign if any gold-plated seats were found. He also called on the opposition leader to do the same if none were found.

Kilicdaroglu denied in a television interview late Monday that he had made such a claim. He said he had referred to gold-plated toilet seats as a general criticism of lavish spending by officials, and that Erdogan "took it personally."

Turkey holds its parliamentary election on Sunday.

Although Erdogan is supposed to be above politics and isn't running, he has been campaigning for a victory by the ruling AKP party, which he led for more than a decade as prime minister. If the AKP wins a large majority, that would enable the party to change the constitution and install a presidential system, which would give the head of state -- now Erdogan -- broad executive powers.

Addressing thousands of people in the eastern city of Kars, Erdogan on Tuesday repeated his call for Kilicdaroglu to step down if he cannot prove the golden-plated seat claim.

He asked the people to support a presidential system at the polls, and slammed a pro-Kurdish and a nationalist party who are also contesting seats in the 550-member parliament.

"There are two parties in our country. One is engaging in Turkish nationalism, the other in Kurdish nationalism," Erdogan said. "Let's teach them a lesson at the polls."