Turkish Prime Minister Tayyip Erdogan accused Western and Arab nations of "double standards" for failing to condemn the overthrow of former Egyptian President Mohamed Morsi, whose Muslim Brotherhood like Erdogan has Islamist roots.
Turkey has emerged as one of the fiercest international critics of what it has called an "unacceptable coup" after Egypt's powerful military shunted the country's elected leader from office earlier this month.
Although the United States has expressed concern at Morsi's removal and called for a swift return to democracy, as has the European Union, it has stopped short of calling it a coup, which might have led to sanctions.
Gulf Arab states, which see Egypt as a strategic ally against any threat from non-Arab Iran, celebrated his departure with palpable relief.
"Countries which embrace and care about democracy should not behave with double standards towards these kinds of events and should say something is wrong when it is wrong," Erdogan told Western, Arab and other ambassadors late on Thursday.
"Those who extol democracy when they meet with us, saying 'one must not compromise on democracy', we want to see their backbone," Erdogan told his guests at a dinner to break the Muslim Ramadan fast.
Erdogan asked why the world stayed silent over the at least 99 people who have died since Morsi was ousted, more than half of them when troops fired on Islamist protesters on July 8.
"Why aren't you speaking up? Come on, speak up against this. There's no point in being ambivalent," he told the diplomats seated around the room at party headquarters in Ankara.
"If you are not going to speak up here, where are you going you to speak?"
Erdogan was feted by adoring crowds in Arab capitals only two years ago when Turkey seemed set to expand its trade and influence across the region on the back of his support for the protesters of the Arab Spring.
Egyptians hailed the Turkish leader as a hero on Tahrir Square in 2011, when he was among the first world leaders to tell Hosni Mubarak his time was up.
But Erdogan's popularity at home and in the region took a dent after a crackdown on nationwide anti-government protests last month in which five people died and thousands were injured.
Egypt's new interim government has warned Ankara not to meddle in its internal affairs and last week summoned Turkey's ambassador to Cairo. Egypt's ambassador in Ankara was not present at Thursday's dinner.
Turkey's response to Egypt is at least partly shaped by its own history of having experienced three military coups since 1960, and the removal of its first Islamist government in 1997, events which Erdogan referred to in his speech.
It is a history not lost on Morsi's supporters.
"Because it has a history of coups, Turkey understands us better and does not want us to go through the same suffering that it has gone through," Abdul Mawgoud Dardery, a former MP from Morsi's Freedom & Justice Party, told Reuters this week.
"Erdogan is still a hero in Egypt and in the rest of the Arab world ... If Erdogan ran for election in Egypt he would most likely win the presidency."