Eight opposition parties have written to Prime Minister Narendra Modi alleging misuse of central investigation agencies to go after them, amid the political war over the arrest of Aam Aadmi Party (AAP) leader Manish Sisodia. The Congress has stayed away from the letter signed by opposition leaders, including Chief Ministers K Chandrashekar Rao, Mamata Banerjee, Bhagwant Mann and Arvind Kejriwal.