Pedro Almodóvar, the leading Spanish film director, has accused the government in Madrid of carrying out a rigorous plan to exterminate Spanish cinema, joining an increasingly angry battle between film-makers and the rightwing governing People's party (PP).

In an article published on the website infoLibre, Almodóvar criticised the finance minister, Cristobal Montoro, for a hike in VAT on tickets which has been widely blamed for causing many cinemas to shut, with the loss of hundreds of jobs. Last week, Montoro said the problems faced by the industry, which include cuts to government funding for domestic films, were nothing to do with taxes or funding, but instead to do with the poor quality of the films.

"Someone should tell this minister … that in France the VAT rate [on cinema tickets] is 7%, and next year it will go down to 5%, in Italy it's 10%, in Germany 11%, compared to 21% in Spain," Almodóvar wrote.

Almodóvar argued that the conflict between traditionally leftwing film-makers and the government dated back to the war in Iraq. "In 2003, Spanish cinema protested … against the war in Iraq … which earned it the hostility of successive governments of the PP. Never mind that 90% of Spanish people were against the war, as demonstrated in the streets across the country," he said.

"Contrary to the will of the people he represented, [the then prime minister, José María] Aznar embarked on the Iraq war in a personal capacity, dragging the whole country with him ... As a result of our 'No War', Spanish film has become the bête noire of the PP government. The current cuts and contempt are the result of that no, which I will never regret, even if not a single cinema remains open."

State funding for Spanish cinema has halved over the past four years. Budget cuts by the cash-strapped government have meant that the national cinematography fund will receive only €33m (£28m) in 2014, a 14% drop on last year.

In his article, Almodóvar defended his right to speak out on public policy, referring to George Clooney's work in Darfur, and Bruce Springsteen's concerts in support of Barack Obama.

"When I hear it said on talk shows that people who work in the arts should not express our political views, I shudder," he wrote. "Does that mean that we don't have the same rights as any other citizen to express what we think? … Political protests should be understood as a civic act and a sign of the health of our democracy."

In a clear reference to the Franco dictatorship, he evoked a past in Spain "guided by one single idea, and where other forms of thought were considered a crime, and therefore punished".

He wrote of the importance of cinema to the social fabric of the country, before signing off: "If Mr Montoro does read this text, which I don't imagine he will, he'll probably think it's written in Chinese."

Montoro last week insisted that the film industry had the complete support of the government, "as one of the sectors of the Spanish economy that generates both economic and cultural wealth".