A statement from the ministry of home affairs said thatSingh will now have Z-plus security instead of SPG, "The current security cover review is a periodical and professional exercise based on threat perception that is purely based on professional assessment by security agencies. Dr. Manmohan Singh continues to have a Z+ security cover," it said.

Congress leaders termed the development unfortunate.

Sources from Manmohan Singh’s office pointed out that UPAhad also reviewed former Prime Minister and senior BJP leader Atal Bihari Vajpayee's security under the amended rules but continued with his SPG cover till his death last year. Singh’s office also said that unlike Vajpayee, who was bedridden after demitting office, Singh actively moves around and there fore is more exposed to security threats.

The SPG was set up in 1985 after the assassination of Prime Minister Indira Gandhi, and Parliament passed the SPG Act in 1988 dedicatingthe group to protecting the Prime Minister of India. In 1989, VP Singh government had withdrawn the SPG protection given to the outgoing PM Rajiv Gandhi.

After Rajiv Gandhi was assassinated in 1991, the SPG Act was amended, offering SPG protection to all former Prime Ministers and their families for a period of at least 10 years. The rule was amended again in 2002to make provision for an annual review. Former prime ministers such as HD DeveGowda also lost their SPG cover after a review.

Sources said the Intelligence Bureau had given a security assessment report in Singh’s case, post which the decision to withdraw the SPGwas taken. Arvind Kumar, director, Intelligence Bureau, had met the former PM last week.

The staff strength of Singh's office was also reduced in June, leading to war of words between the BJP and Congress, with the latte rarguing that UPA had left Vajpayee's office staff strength untouched and it shouldbe reciprocated by the NDA.

Manmohan Singh was Prime Minister for 10 years from 2004 to2014. His daughters had given up their SPG cover after his tenure gotcompleted.