Prime Minister Datuk Seri Najib Tun Razak said he was prepared to accept suggestions and criticisms but not when they are uncalled for.

In his latest official Facebook posting, he said he had to take action against Taiping member of parliament Nga Kor Ming.

"I am prepared to accept suggestions and criticisms on my leadership, policies and administration but DAP MP Nga Kor Ming's remark, with a photograph of my wife and I in his Facebook, was derogatory and malicious.

"Hence I have instructed my lawyer to send a letter of demand to Nga Kor Ming for an apology and if he fails to do so, I will take legal action," he said.

The prime minister and his wife Datin Seri Rosmah Mansor through legal firm Hafarizam Wan & Aisha Mubarak, yesterday sent the letter of demand to Nga, who is also Pantai Remis assemblyman.

Nga allegedly uploaded a status accompanied with a photograph, titled, 'Nga Kor Ming: Who is the real prime minister of Malaysia? Answer!'.

In the letter of demand, the legal firm asked Nga to remove the status from his Facebook and refrain from making defamatory remarks about Najib and Rosmah within 48 hours from yesterday.

The letter demanded that Nga issue a written apology, and retract the alleged defamatory status within 48 hours.