For decades, British politicians have cowered in fear at the power of the nation’s popular and largely unregulated tabloid newspapers, which are owned by a handful of billionaires, and skew heavily to the far right.

The current Conservative government is no exception. Prime Minister Theresa May reportedly met with Rupert Murdoch, who owns the Sun, soon after she took power. The man May put in charge of negotiating Britain’s complex exit from the European Union, David Davis, left the first day of talks in Brussels after just an hour so that he could get back to London for a private dinner with Paul Dacre, editor of the Daily Mail.

So the prime minister presumably thought it would be good politics to joke on Wednesday in the House of Commons about a smear campaign launched by the tabloids on Jeremy Corbyn, leader of the opposition Labour party. Referring to a recent barrage of poorly sourced stories in the Sun and the Mail accusing Corbyn of having helped Czechoslovakia spy on Britain during the Cold War, May introduced a tortured pun about the Labour leader wanting her to sign “a blank Czech.”

Corbyn’s response, a theatrical yawn, delighted his supporters.

A more potent sign that the attacks had failed was how quickly other members of May’s party retreated when the allegations about Corbyn were thoroughly debunked by former British spies and records available in the archives of the Czech secret service. Those records, an archivist told the BBC, showed only that a spy posing as a diplomat had spoken with Corbyn in the 1980s, but had not recruited him as a source.

The former spy, Jan Sarkocy, whose testimony against Corbyn is the only source for the slew of British newspaper stories branding the Labour leader a traitor, subsequently undermined his own credibility in an interview with a Czech newspaper, Novy Cas. Asked what kind of information Corbyn had provided to him, Sarkocy boasted that it was so detailed that he knew what then-Prime Minister Margaret Thatcher ate for breakfast each day and what clothes she planned to wear one day in advance.

Sarkocy did not explain how Corbyn — who was then a marginal figure on the far-left of the opposition Labour Party — would have known such intimate details about the daily habits of the far-right, Conservative prime minister.

The former spy then boosted suspicions that he was a fabulist by also claiming to have secretly organized a huge pop concert at Wembley Stadium in the late ’80s — apparently confusing the Live Aid concert in 1985 with a tribute to Nelson Mandela in 1988. “It was funded by Czechoslovakia,” Sarkocy told the Czech paper.

The absurdity of the former spy’s claims inspired even Andrew Neil, a former editor of the Murdoch-owned Sunday Times, to eviscerate a Conservative member of Parliament, Steve Baker, for refusing to admit that the story his colleagues had promoted was false. “Surely the real scandal,” Neil told Baker, “isn’t what Mr. Corbyn has supposedly done, or not done, it’s the outright lies and disinformation that your fellow Tories are spreading.”

Faced with the threat of legal action for having libeled Corbyn, another Conservative MP, Ben Bradley — previously best-known for having advocated the sterilization of the poor — deleted a tweet in which he falsely claimed that “Corbyn sold British secrets to communist spies.”

Corbyn’s lawyers have demanded that Bradley also tweet an apology for having made the accusation and make a donation to a charity of the Labour leader’s choice.

On Tuesday night, Corbyn replied to the smear campaign in a video statement that quickly racked up more than 1.5 million views on social networks, in which he called the former spy’s claims “increasingly wild and entirely false.”

Corbyn also signaled that he would not be following the example of Labour’s former leader Tony Blair, who had courted Murdoch and other tabloid owners. Instead, Corbyn hinted, the newspapers should brace themselves for more regulation should he come to power.

It’s easy to laugh, but something more serious is happening. Publishing these ridiculous smears that have been refuted by Czech officials shows just how worried the media bosses are by the prospect of a Labour government.

A free press is essential for democracy and we don’t want to close it down, we want to open it up. At the moment, much of our press isn’t very free at all. In fact it’s controlled by billionaire tax exiles, who are determined to dodge paying their fair share for our vital public services.

The general election showed the media barons are losing their influence and social media means their bad old habits are becoming less and less relevant. But instead of learning these lessons they’re continuing to resort to lies and smears. Their readers — you, all of us — deserve so much better. Well, we’ve got news for them: Change is coming.

Faced with overwhelming evidence that their effort to tie Corbyn to Czech intelligence had failed, reporters for the far-right tabloids moved on to loudly demanding that the Labour leader permit the release of a supposed file on him compiled by the East German secret service, the Stasi. That effort also fell flat when German officials who oversee the Stasi archive announced that they had found no documents at all on Corbyn.