New Delhi/IBNS: Eight opposition parties have written to Prime Minister Narendra Modi alleging misuse of central investigation agencies to go after them, in the backdrop of the arrest of Aam Aadmi Party (AAP) leader Manish Sisodia.

The Congress, however, stayed away from the letter signed by opposition leaders, including Chief Ministers K Chandrashekar Rao, Mamata Banerjee, Bhagwant Mann, and Arvind Kejriwal.

Others who have signed the letter are National Conference's Farooq Abdullah, Nationalist Congress Party chief Sharad Pawar, Sena's Uddav Thackeray, Samajwadi Party chief Akhilesh Yadav, and Bihar Deputy Chief Minister Tejashwi Yadav.

The Enforcement Directorate (ED) is investigating the Gandhis over alleged money laundering linked to Young Indian's takeover of Associated Journals Ltd, the company which ran the National Herald newspaper.

Both Rahul Gandhi and his mother Sonia Gandhi were questioned by the ED last year.

"We hope you would agree that India is still a democratic country. The blatant misuse of central agencies against the members of the opposition appears to suggest that we have transitioned from being a democracy to an autocracy," the letter said.

"... After a long witch-hunt, Manish Sisodia was arrested by the Central Bureau of Investigation (CBI) in connection with alleged irregularity without a shred of evidence against him," the opposition leaders said in the letter to PM Modi.

"Out of the total number of key politicians booked, arrested, raided or interrogated by the investigation agencies under your administration since 2014, the maximum belongs to the opposition. Interestingly, investigation agencies go slow on cases against opposition politicians who join the BJP," the letter said.

The opposition leaders cited the example of Assam Chief Minister Himanta Biswa Sarma, who was under the scanner of the CBI and the ED in 2014 and 2015 over the Saradha chit fund scam when he was with Congress.

"However, the case didn't progress after he (Mr Sarma) joined the BJP. Similarly, former TMC (Trinamool Congress) leaders Suvendu Adhikari and Mukul Roy were under the ED and CBI scanner in the Narada sting operation case, but the cases didn't progress after they joined the BJP ahead of the assembly election in the state (West Bengal)," the letter alleged.

"Since 2014, there has been a marked rise in the number of raids conducted, cases lodged against and arrest of the opposition leaders. Be it Lalu Prasad Yadav (Rashtriya Janata Dal), Sanjay Raut (Shiv Sena), Azam Khan (Samajwadi Party), Nawab Malik, Anil Deshmukh (NCP), Abhishek Banerjee (TMC), central agencies have often sparked suspicion that they were working as extended wings of the ruling dispensation at the centre. In many such cases, the timings of the cases lodged or arrests made have coincided with elections making it abundantly clear that they were politically motivated," the opposition leaders said in the letter.

Sisodia was arrested for alleged corruption in framing a liquor policy for Delhi.