A Libyan rights group said on Wednesday it will mount a challenge in the supreme court against laws which criminalise the glorification of Moamer Kahdafi's ousted regime and insulting Islam. "This is the first time a decision or law passed by the National Transitional Council (NTC) will be appealed in court," Mohammed Allagi, who heads the General Liberties and Human Rights Council, told AFP. Allagi, a former jutice minister, said his group had taken "all steps necessary to appeal as unconstitutional the laws that have been passed in contradiction to the (NTC) constitutional declaration," which protects freedom of speech. A series of laws passed on May 2 by the ruling authorities marked a "dangerous regression" and a "gross violation of public freedoms and human rights," he charged. One of them criminalises the glorification of slain strongman Kadhafi, his regime or relatives. The law prescribes prison sentences for spreading false rumours, information or propaganda that hamper national defence, spread terror or weaken morale. Backers of the law argue it does not target the media specifically and point to the example of Germany which outlawed Nazi parties after World War II. But Allagi said such a law was not necessary in Libya where backers of the former regime were not a widespread or visible threat to society. Harming the February 17 revolution which toppled Kadhafi last year, insulting Islam or offending the state and its institutions have also become criminal offences. The length of prison terms are not spelled out but based on the penal code they could range between three and 15 years. Allagi, who served as interim justice minister in 2011, said he would file the appeal with the supreme court. In mid-April, he launched the Free Libyans Party with the hope of fielding candidates in elections for a constituent assembly scheduled to take place in June.