Independent Senator Nick Xenophon has slammed the major parties for blocking his moves for an inquiry into the Church of Scientology.

Senator Xenophon has been calling for a full inquiry into the church since revealing claims of forced abortions and other abuses in Parliament last year.

Today he accused Prime Minister Kevin Rudd of hiding behind process and vowed to continue to fight for further examination of Scientology in Australia.

"There is a certain cowardice in turning your backs on people who ask for help and ask just to be heard," he said.

"I ask Kevin Rudd and [Opposition Leader] Tony Abbott, what is it about forced abortions you do not want to know about?

"What is it about false imprisonment that you don't want to know about? I will not turn my backs on the victims of Scientology. I will not let this lie. This issue will not go away."

Senator Xenophon now says he will move another motion for an inquiry into the church, which he says will focus on specific allegations made against it, next week.

Today Senator Xenophon moved for a broader inquiry into the tax-free status of religions when it was clear he did not have the numbers for his original Scientology probe.

However, the Opposition and Government blocked the motion.

Senator Xenophon said the Government told him it could not support the tax inquiry because it could pre-empt the still-to-be released Henry Tax Review.

Special Minister of State Joe Ludwig says the tax-free status of various organisations has already been extensively covered by other inquiries and another is not needed.

"Based on this detailed and comprehensive record of an analysis and in light of two current review reports before the Government, we will not be supporting this motion today," he said.

The Greens supported the motion but that was not enough to get it passed.

"I do object and I know many other Australians object to millions of dollars being siphoned off from the public purse because we haven't refined our ability to say a dangerous cult ought not be getting that money," Greens leader Bob Brown said.

Liberal Senator Eric Abetz expressed sympathy for anyone who had suffered under the Church of Scientology but said the Senate was not the right place to hear their stories.

He also questioned whether a Senate inquiry would stop people being "brainwashed" by various organisations.

"Whilst the motion on the face of it looks relatively innocuous, talks about a general inquiry into matters tax and charitable status generally, there is no doubt from the speeches of Senators Xenophon and Brown ... that it would not just be a general discussion of matters taxation," he said.

ABC's Four Corners program also this week broadcast allegations from ex-members of Scientology of forced abortions, pressure to work extreme hours and being pressured* to hand over large sums of money.

*Editor's note: (June 17) The article originally reported that ex-members of Scientology were being "forced" to hand over large sums of money. It is more accurate to say that people were being put under "pressure" to hand over money. This matter was reported correctly in the ABC's Four Corners program.