He told a press conference at a hotel in Petaling jaya this morning that his decision was because he felt PKR was now far from its struggles as declared when he first joined the party in 1999.
It was reported earlier that Dr Halili had contested and lost in past elections namely for the Kuala Kubu Baru and Batang Kali state seats.
Then in the 1999 general elections he was beaten by former Hulu Selangor MP Datuk G. Palanivel by a 8,595 vote majority.
Dr Halili, reportedly the first Malay neurosugeon in the country, is from a kampung in Batang Kali.
He is also fiercely loyal to Datuk Seri Anwar Ibrahim and they are said to be related or what the Malays term as bau-bau bacang (reminiscent of the bacang fruit or distant relative).