More than 200 Indian academics, activists and journalists have published an open letter urging the Indian government to withdraw last week’s decision sanctioning the prosecution of the Booker prize-winning author Arundhati Roy under the country’s stringent anti-terrorism law.

“We … deplore this action and appeal to the government and the democratic forces in the country to ensure that no infringement of the fundamental right to freely and fearlessly express views on any subject takes place in our nation,” the group said in the letter.

One of the signatories, the history professor Ajay Dandekar, said the decision was unjustified. “The Indian constitution upholds Roy’s right to the freedom of her opinions and we are a constitutional democracy,” he said.

Others also voiced support for Roy, including the Samyukt Kisan Morcha, an umbrella group of farmer unions, which condemned the decision. A few protests by civil rights groups, activists, and students in Delhi and Bengaluru have also taken place.

Last week the lieutenant governor of Delhi, Vinai Kumar Saxena, gave the go-ahead to the police to prosecute Roy, along with the academic Sheikh Showkat Hussain, under the anti-terrorism law, known as the Unlawful Activities Prevention Act (UAPA), for remarks they made at a seminar in 2010.

Roy is reported to have said the disputed region of Kashmir had never been “an integral part of India”.

Ever since Roy’s literary success in 1997, when she won the Booker prize for her debut novel The God of Small Things, she has been a sharp critic not only of Narendra Modi’s government but of previous governments too. She has attracted praise and censure in equal measure for her critiques of capitalism, the treatment of minorities, and globalisation, as well as her support for human rights causes.

However, the decision to prosecute her under the law, which makes bail difficult and results in people spending long years in prison awaiting trial, has shocked some Indians.

“Are we a democratic country or not?” asked Mukta Manohar, the general secretary of the Pune municipality Safai union, one of the signatories. “We signed the letter because we have to uphold our constitutional right to disagree with the government. We can’t let the government take revenge against critics like Roy out of some personal whim.”

Arnab Goswami, an unapologetically pro-Modi TV anchor, expressed his “delight” at the lieutenant governor’s decision.

“I’m very happy that Arundhati Roy, that terrorist supporter, that Maoist sympathiser, what I call a Gucci separatist, who made speaking against India a career option when her books failed, is finally going to be prosecuted,” said Goswami.

What remains unclear is why the decision to prosecute has been taken at this particular moment, when the complaint against her, filed by someone who attended the seminar, has been pending with the police for 14 years without being pursued.

Lawyers say they are puzzled as to why such a draconian law has been invoked. The supreme court lawyer Sanjay Hegde thinks that if Roy had been prosecuted under other, less harsh laws such as those dealing with provoking disharmony or inciting enmity among certain groups, the government would have run foul of the statute of limitations. No such limitation applies to the UAPA.

Nonetheless, Hegde thinks the case will be challenged in the courts at a very early stage for two reasons.

“The police will have to explain the 14-year delay and also explain why she should be charged when her words have not resulted in any violence or criminal acts in all this time,” he said.

The human rights lawyer Colin Gonsalves agreed that the case, if the government goes ahead, could collapse at the first hurdle. “It’s a crazy decision and they won’t be able to prove that Roy was linked to any violence or any efforts to overthrow the state. The prosecution is unlikely to succeed,” he said.

Nor is it clear whether the decision to sanction action against her is based on evidence that has emerged from a police investigation or whether it is expected to emerge from a police investigation that is still to take place.

Some liberals had hoped Modi’s reduced majority in the recent general election and his dependence on two regional parties could herald a more tolerant approach to dissent.

But Hegde said the opposite seemed to be happening and that Roy had been chosen as a target for being a “low-hanging fruit” in that she is seen as representing a broad swathe of intellectuals and activists ranged against the government.

Even if the prosecution failed, he said, it would send a loud message to Modi’s critics that keeping quiet was their best option because one day the state may come looking for them under the UAPA.

“The message is, don’t think that given our reduced mandate, we are going to be any nicer. If anything, we may be even harsher than before,” said Hegde.