By Katya Adler BBC correspondent in Madrid

Spain holds an election in three weeks' time. Opinion polls show that many Spaniards are still undecided as to how they will vote.

The government is criticised for not changing a biased media law

Politicians up and down the country are on the campaign trail.

That and information in the Spanish media should help people make up their minds.

Yet there are nagging doubts at home and abroad.

The International Federation of Journalists has criticised the lack of impartiality in the Spanish press.

In Spain, a number of writers, academics, singers, journalists and actors have set up a platform to lament the absence of open political debate.

There are those who blame this on Spain's relatively young democracy.

"The Spanish press is filled with silences... This is a left-over of dictatorship Emilio Silva Freelance journalist

The Spanish constitution was signed only 25 years ago, on the back of 40 years of fascist dictatorship under Francisco Franco.

"The Spanish press is filled with silences," freelance journalist Emilio Silva said.

"So often when I'm out to lunch with another journalist, they say to me 'Oh I wish I could write this report or that report,' but they can't because they are subject to unofficial political censures.

"This is a left-over of dictatorship."

Choice?

Yet a visit to one of Madrid's numerous newspaper stands will show you that choice is not the problem.

There are countless newspapers, magazines and also private radio and television stations.

The problem for many Spaniards though is that each one has a distinct political bias.

This, of course, is common the world over in the privately-owned media but Spain's public broadcaster, too, has come under fire.

Of course the director general of the news output at Television Espanola has political opinions, we all do, but he is doing his best in his job Gustavo de Aristegui MP for the Popular Party

Last month, the Parliamentary Assembly of the Council of Europe cited Spain's public radio and television channels as an example of "news manipulation".

At Television Espanola itself, over half the employees formed an independent Advisory Council, in the face of what they describe as "the growing manipulation which is seriously undermining the credibility of the public channel and its workers".

The roots of the problem lie in Spanish law.

Maria Pilar, a professor of media law at Madrid University explains that according to a law passed in 1980 to regulate the public broadcaster, Spanish radio and television cannot be anything but politicised.

"Every time there is a general election in Spain, the new prime minister appoints the head of the public broadcaster," she said.

"The committee elected to help them in their job is then also newly formed to represent proportionately the size of each political party in parliament.

"How can Spanish public television and radio not be politicised with this law?

Public TV is accused of censoring criticism from soldiers' families

"Of course the opposition parties always say they'll change it .. but when they get in to government, it is no longer in their interest to do so."

Gustavo de Aristegui is a member of parliament for the conservative Popular Party in government.

The Popular Party flatly denies wielding any untoward influence in the media.

But I put it to Mr Aristegui that, according to the 1980 law, any government that holds an absolute majority in parliament, like this one, must therefore also have absolute influence over the public broadcaster.

"That is preposterous!" came the reply.

"Of course the director general of the news output at Television Espanola has political opinions, we all do, but he is doing his best in his job and it is insulting to the professional integrity of the workers at TVE to suggest they are being controlled by the government."

But Curra Ripolles, an employee at Television Espanola, says she has personal as well as professional experience of government influence at the public broadcaster.

In May last year, her brother was one of 62 Spanish peacekeepers killed on their way home from Afghanistan when their plane crashed over Turkey.

Elections

The flight had been chartered by the Spanish government and the families of those who died accused the government of having taken a cheap rather than safe option.

They said the plane was not technically sound.

"TVE would not broadcast our complaints, though," Ms Ripolles said.

"It just kept broadcasting the government line that the pilot was to blame for the crash.

"This put me in a weird situation, fighting the organisation that pays my wages."

Many Spaniards say they are missing a more balanced view, a neutral voice from the public broadcaster.

A recent public opinion poll, for example, showed that 75% of Spaniards want a televised, live head-to-head debate between the two main contenders for the general election.

They want to judge the leaders of the Spanish Socialist Party and the conservative Partido Popular for themselves.