Scotland's controversial anti-sectarianism laws have come under attack in a new publication by one of the nation's leading cultural bodies.

The Saltire Society is publishing a series of pamphlets to ignite debate on contemporary issues, and a new tract, published today, sees writers Alan Bissett and Jean Rafferty criticise the Offensive Behaviour at Football and Threatening Communications Act of 2012.

The Act created two new offences, one dealing with offensive behaviour relating to football games, and a second on threatening communications, and aims to stamp out the chanting of offensive slogans or songs.

Penalties range from a £40 fixed fine to a maximum of five years in prison and an unlimited fine.

However in the new pamphlet, Freedom of Expression in the New Scotland, Bissett, the author of several novels and plays, says the Act is damaging to free speech.

Bissett, a supporter of Scottish independence, said the Act was well meaning but misjudged.

"While one might think some of the songs sung by Rangers and Celtic supporters ugly, and opprobrium is fine, it is not the place of government to circumscribe which political slogans can and can't be sung by adults," he writes.

"That this is the one issue to unite Old Firm fans in recent decades speaks volumes about the government's unwelcome interference."

He said that it is within people's rights to criticise the Catholic Church, the IRA, the monarchy or the legacy of British imperialism and it is also a right to "assert our Irishness or our Britishness".

"These are identities. We run into immediate problems of censorship when the government decides which ideologies are unchallengeable and which identities beyond reproach," he adds.

"We should be much more cautious when it comes to race, as skin colour is not an intellectual or emotional choice. But race is not at the heart of this Bill."

Mr Bissett adds that some songs or chants are unacceptable when they refer to racial identity, but in other cases "outrage might be appropriate, but not censorship."

Ms Rafferty, a novelist and award-winning journalist, said the Act is unworkable in practical terms and "quite unnecessary", a "charter for disaster" and writes: "Who decides where to draw the line between sectarianism and strong comment?

She adds: "Not only is the 2012 Act unworkable in practical terms, it's quite unnecessary. Our current laws are already equipped to deal with comment when it tips over into hate speech."

Jim Tough, executive director of the Saltire Society, said: "The launch of the new series of pamphlets asserts our proper position as a platform for free and independent thinking on the issues that matter most to Scotland today. We believe our role as an independent, apolitical cultural commentator is as vital today as it ever was. This passionate dialogue between two of our foremost writers is a timely exploration of the freedom of expression."

l Freedom of Expression in the New Scotland is published by the Saltire Society in partnership with Scottish PEN.