The NoToPope Coalition protesters object to several Catholic moral teachings and Ms Evans - emboldened by the court triumph - immediately went and handed more condoms to Catholic pilgrims posing for photographs outside a nearby church.

Wearing an anti-Pope T-shirt, for which she might previously have been fined as much as $5500, Ms Evans called it a "major victory for the protest movement".

A full bench of the court, comprising Robert French, Catherine Branson and Margaret Stone, had ruled that part of the World Youth Day Act, passed by the NSW Parliament to keep order during this week's events, "should not be interpreted as conferring powers that are repugnant to fundamental rights and freedoms at common law in the absence of clear authority from Parliament".

The court struck the words "annoyance or" out of World Youth Day regulations, which originally referred to "conduct that causes annoyance or inconvenience to participants in a World Youth Day event".

The Premier, Morris Iemma, reacted to the ruling as he accompanied Catholic youths on a tour of Sydney streets yesterday.

"The court has struck out two words," he said. "Inconvenience is still there. It achieves the same objectives. People who want to make a point, if it's a protest, can do so, without disrupting the pilgrims or the events."

The Government and police said the ruling would have no effect on policing of the six-day event, which officially began yesterday.

But Ms Evans and Ms Pike are determined to spread their message and are composing a new set of commandments.

By 4pm yesterday they had drawn up six, the first being, "Thou shalt not condemn millions of people to death" (by exposing them to AIDS). The second was: "Thou shalt not preach to women about their reproductive choices."

They were confident they would be promulgating their commandments by Sunday, the day of the final Papal Mass. They were also busy last night filling envelopes with letters and condoms for distribution.

Ms Evans had already given condoms to pilgrims in Hyde Park. "The response of some was good, others not so good. But we were able to talk to people about condoms and contraception, which they had been brought up to think of as intrinsic sin."

Outside the court some international visitors accepted the condoms before dropping them with distaste once they realised what they had been given.

The judges found partially for Ms Evans and Ms Pike, who had applied to have the World Youth Day Act 2006 invalid, on the grounds it "impermissably" burdened "the implied freedom of communication on matters of government or politics arising under the Commonwealth Constitution". They also found the concept of annoyance had "no intelligible boundary".

But they found the right to act over "inconvenience" was more applicable because it did have some "objective elements" when applied in situations were someone was hindering or obstructing movements.

Ms Evans, a student in Spanish at the University of Technology, Sydney, called on the Pope to "get real and allow people to discover their sexuality and practise with condoms".

The president of the NSW Law Society, Hugh Macken, said the law against being "annoying" was always going to be difficult to enforce. "To think that you could make participants in World Youth Day illegal by regulation was ill-thought," he said. "The other observation in the judgment was that the Government was attempting to do something by regulation which clearly needed the sanction of Parliament."

Terry O'Gorman, the president of the Australian Council for Civil Liberties, said there was still need for a charter of rights to reinforce fundamental liberties such as freedom of speech.

The law as it stood was "not sufficient to protect against attacks on free speech", he said.

There was also the need for balance between protection of the public and infringement of civil liberties, as was the case when special laws enacted for the Asia-Pacific Economic Co-operation conference had become entrenched in law.

The Police Commissioner, Andrew Scipione, said: "People have a democratic right to [protest]. But with that right comes a responsibility to act within the law. I hope those who do protest are mindful that this state is playing host to thousands of guests who have come here in a very positive and festive frame of mind."

A senior officer said police had not intended to use the annoyance rules because they had not been told how to interpret them.