The advert entitled "The word of God Against Sodomy" was placed in the News Letter during the summer by the Rev David McIlveen's Sandown Free Presbyterian Church in east Belfast.

The church is angry that the Advertising Standards Authority (ASA) ruled the advert, which used biblical verses to condemn homosexual practices and called for a protest against the Gay Pride Parade in Belfast, was indecent.

Dr Paisley, who founded the church, has backed Mr McIlveen's stand and is supported by current Moderator the Rev Dr Ron Johnson.

The ASA has now ordered the church to submit any future adverts for approval, a condition the church has said it "cannot and will not" submit to.

It is understood that seven people, who remain anonymous, complained about the advertisement.

Speaking at a Press conference at Mr McIlveen's church yesterday, Dr Paisley said the issue was wider than just the advertisement, and encompassed fundamental issues of "civil and religious liberty" and the freedom to publish biblical extracts.

He said: "We believe the Bible is the written word of God – the infallible word of God, and it has to be obeyed, so we will obey God rather than men, and if it means there has to be court proceedings, if it means even that we are going to be jailed for holding on to this, then that's a price we have to pay, and we are prepared to pay it."

Dr Paisley also called for action against Gay Pride marchers who offended Christians and broke the law.

Last year, one marcher carried a placard reading "Jesus is a fag", while this year a man allegedly exposed himself to anti-gay protestors.

The former Free Presbyterian Moderator said the placard was offensive to all Christians, while the lewd act was offensive to all decent people.

He said: "I am amazed at the dragging of the feet of the police on a thing like this.

"If it had been on the other side of the water, there would have been instant statements even in Parliament about it, but instead of that it seems to have been pushed on the long finger."

He said he was also concerned that those objecting to the advert could remain anonymous, while those accused stood in the full glare of publicity.

Dr Paisley said if people were offended they should come out and make their case publicly.

"I don't like that people who remain anonymous can charge anybody they like and the Government can take heed of these anonymous accusations, and as a result castigate those who are known to be upholders of law and order."

The ASA said yesterday that if either an advertiser or a complainant had a problem with any of its rulings, they were free to take it to the Independent Reviewer and would not comment any further on the matter.

No-one from the Gay Pride march organisers was available for comment yesterday

The PSNI yesterday said it was still looking into the alleged Gay Pride march incidents.