Dear Editor

We the undersigned have detected a recent resurgence in open letters to newspapers and would like to explore this further.

How effective are they? What's the key to a good open letter? Why are so many springing up now?

Yours faithfully

Concerned readers

Subjects as diverse as regional theatre, fiscal policy and trouble with the in-laws have all been recently tackled by open letters to newspapers. It's become a widely used tool to register disapproval, set out one's position or simply let off steam.

Fifty-three MPs urged reform of drugs policy, 46 actors protested about cuts to regional theatre and 33 barristers opposed a British Bill of Rights, all in recent days.

The use of an open letter to newspapers, with dozens of signatories, has become an increasingly common form of protest.

In one sense, all letters that are published are open, but some are consciously intended for a wider audience. Although addressed to an editor, it's doubtful the writer gives two hoots what a man behind a desk in a newspaper office really thinks. The message is often intended to fall on the ears of a government minister.

Dear sir, we support/condemn: Forests privatisation

NHS changes

Arts funding cuts

Tuition fees hike

Bill of Rights

Drugs policy

High-speed rail

Many open letters have one author but it's the group missives that have caught the eye in recent months. In one week last year, the Guardian published nine letters which had more than one name on them.

The editor of the letters page, Nigel Willmott, has expressed his concern at this trend, which he links to "times of greater social or political tension", and mentioned the public sector cuts and the economic downturn as galvanising influences. It was inappropriate, he said, for letters to be clearly aimed at any audience other than the newspaper and its readers.

But it's a tradition that goes back centuries. Katrina Navickas, a historian of the protest movement at the University of Hertfordshire, says it was a common tactic from the late 18th Century onwards, when newspapers were taking off.

"The anti-slavery movement in the early 18th Century and early 19th Century used the national press like the Times, but the provincial papers were even more important, like the Manchester Guardian and the Leeds Mercury.

Two famous open letters In 1898, writer Emile Zola 's letter J'Accuse was published on the front page of French newspaper L'Aurore. It was addressed to France's president, Felix Faure, and accused the government of "shameful" anti-Semitism in what Zola believed was the unlawful imprisonment of army officer Alfred Dreyfus for alleged espionage. Zola was convicted of libel and fled to England

's letter J'Accuse was published on the front page of French newspaper L'Aurore. It was addressed to France's president, Felix Faure, and accused the government of "shameful" anti-Semitism in what Zola believed was the unlawful imprisonment of army officer Alfred Dreyfus for alleged espionage. Zola was convicted of libel and fled to England And in 1963, Martin Luther King wrote a letter from jail in Birmingham, Alabama, which supported non-violent direct action in the civil rights movement. It included the famous line: "Injustice anywhere is a threat to justice everywhere".

"They're the important papers, rather than the national press, which are still seen as quite London-centric, so even national campaigns like those opposed to slavery use local papers as platforms."

One of the most influential letters, says Navickas, was sent to the Leeds Mercury in 1830, by English labour campaigner Richard Oastler and entitled Yorkshire Slavery:

Thousands of our fellow-creatures and fellow-subjects, both male and female, the miserable inhabitants of a Yorkshire town, (Yorkshire now represented in Parliament by the giant of anti-slavery principles) are this very moment existing in a state of slavery, more horrid than are the victims of that hellish system 'colonial' slavery.

The concern and debate it generated helped his campaign to bring about the 1833 Factory Act, which restricted the use of children in the textile industry, says Navickas.

There have been many powerful examples by individuals, such as Emile Zola's letter condemning the French government, the title of which, J'Accuse, has become part of the English lexicon. Martin Luther King also penned the famous line "injustice anywhere is a threat to justice everywhere" in a letter from his prison cell.

One of the most famous British cases was in 1981, when 364 economists signed a letter to The Times, urging Chancellor Geoffrey Howe to abandon his monetarist policies. But the economy began to grow days shortly afterwards. Many of the signatories, which included two past and future Nobel Laureates, several future Blair advisers and one future governor of the Bank of England, still stand by their decision.

The ones that have made the news in the past year may not have matched Luther King or Zola for impact, but they provided impetus to the news cycle when they echo the paper's political agenda.

And following Emile Zola's tradition... Facebook founder Mark Zuckerberg penned an open letter to members in 2006 to apologise after many raised concerns about privacy

penned an open letter to members in 2006 to apologise after many raised concerns about privacy Chef Gordon Ramsay wrote to his mother-in-law, in an effort to heal a family rift

wrote to his mother-in-law, in an effort to heal a family rift Actress Samantha Morton tried in vain to trace her stepfather

tried in vain to trace her stepfather Broadcaster Anna Ford made a personal attack on writer Martin Amis

The array of acting talent that wrote to the Observer about arts funding, including Helen Mirren, Kenneth Branagh and Julie Walters, was stellar enough to make the news section. Likewise, when business figures have grouped together to support or attack the coalition's economic policies, it has invariably made a splash.

In February, 88 Liberal Democrat councillors attacked the pace of the spending cuts, in a letter to the Times. That sparked several days of political stories about tensions within the party and within government. And when 15 university vice-chancellors supported an increase in tuition fees last year in an open letter, it was used to rally support ahead of a Commons vote.

Whereas in the past some campaigning groups may have splashed out on an advert in a newspaper, they can now make their point free of charge in the letters page.

"Keith Flett, London N17" is one of the most familiar signatures on British letters pages, rounding off hundreds of submissions to newspapers and magazines annually.

You have to be succinct. But you have to have a feel for what's going to make would-be signatories say, 'Yes, that's fine with me Keith Flett, Prolific letter writer

But Flett, a historian, insists that he only organises one or two round-robin letters with multiple signatories each year, because the effort involved in doing so is much greater than the casual reader might imagine.

And although he recognises the power of social media websites, he insists that newspaper letters pages still carry far greater authority than any Twitter feed, Facebook profile or blog.

"It's no easy matter, believe me," he says. "You have to be succinct. But you have to have a feel for what's going to make would-be signatories say, 'Yes, that's fine with me.'

"You have to be able to get hold of them all and often you have to do it quite quickly so the letter can make the biggest impression. There's a lot of work goes into their production.

"It does have an impact. I very rarely get someone coming up to me and saying, 'I saw that tweet of yours.' But if I get a letter in a paper, people will say, 'I read that.'"

Image caption The old-fashioned methods are dying out

It's easier to mobilise support now, says media commentator Vincent Graff, because it's quicker to send an e-mail around looking for supporters than it is to get a researcher to make 10 phone calls. But he's doubtful about how much an open letter changes people's minds.

"I don't think they do have a huge impact. They can plant the seed of an idea, but they're never going to change policy.

"If a letter is published on a Monday, it won't change policy by Tuesday. But it can plant the seed in public opinion, so people may think 'this isn't quite right' and it can lead to pressure on the government."

They won't change anything on their own but they can be part of a movement, he says.

"The ordinary person might look at it and think 'I never thought this was right but now very clever people are saying it too'.

"So it's good for campaigners and it rallies your own side rather than knock down the other side, especially when 24 hours later you see the opposing view in another open letter in another newspaper."

Open letter ping-pong.

By Tom Geoghegan and Jon Kelly