At least one member of the federal government stands opposed to mandatory internet censorship, with Senator Kate Lundy pushing the Minister for an "opt-out" alternative from the online blacklist.

But Lundy says she has "a job cut out for me" lobbying colleagues before legislation is introduced to parliament next month. The former Labor front-bencher and passionate advocate for open IT has told Crikey she believes "the majority of caucus" wants a mandatory filter in place.