"The then Karnataka Chief Minister Rama Krishna Hegde had to step down following similar allegations. Till the time Modi's name is not cleared, he should step down," JD(U) General Secretary K C Tyagi told reporters here.
He said a sitting judge of the apex court should investigate the case, a demand also raised by Congress women leaders including Union Ministers Girija Vyas and Jayanti Natrajan.
He dubbed as "utterly unethical" the use of state machinery and the ATS to "snoop on the private life of a young woman".
He said the incident showed that democratic norms in Gujarat have suffered under the rule of Narendra Modi.
JD(U) had parted ways with BJP in June on the issue of projecting Modi as the Prime Ministerial candidate.
Tyagi also demanded that the bail of former Gujarat minister and Modi's aide Amit Shah be cancelled immediately.
