The founder of Britain’s anti-immigrant and euroskeptic U.K. Independence Party (UKIP) condemned the party’s rightward shift on Wednesday in an op-ed, where he wrote: “I created a monster.” Alan Sked, who founded the Anti-Federalist League (that later came to be called the UKIP) in 1991, said the party had drifted from its original ideals of opposing European bureaucracy to espousing a message of racism and xenophobia.

“I no longer recognize the party I founded. In the years since I stepped down as its leader, UKIP has become a vehicle of the far-right, obsessed with race and immigration,” Sked wrote in the Atlantic. “The party, in other words, could destroy the cause for which it was created. My dream has turned into a nightmare.”

Sked discussed the history behind the AFL’s rise, saying he was inspired by the pro-free trade policies pursued by former prime minister Margaret Thatcher. He stressed that the party was designed to focus on the European Union and its overreach, and not on immigration. “The party did not formulate policy on immigration. ... In fact, UKIP’s party-membership form during this period stated that its members had no prejudices against foreigners or minorities,” he wrote.

Exiting the EU is still a central part of UKIP’s platform, but the party has expanded its portfolio in recent years to include opposition to immigration. While its message has found purchase among voters who feel that unrestricted immigration has harmed the British economy, UKIP has found itself dogged by charges of racism, both for its policies and for statements made by its members.

“UKIP has become an extreme nationalist and populist party, fixated on immigration and on leaving the EU so that the United Kingdom can regain control over who crosses its borders,” Sked wrote. “A party that was once moderate, outward-looking, and devoted to preserving parliamentary democracy has mutated into a conduit for right-wing xenophobia, Islamophobia, homophobia, racism, and the denigration of immigrants.” 

Sked’s vitriol for his former party has been ongoing since it began racking up electoral victories in 2013. Last year, he called UKIP’s current leader Nigel Farage a “dim, racist alcoholic,” and criticized his praise for Russian President Vladimir Putin. “Putin is clearly a nasty piece of work and Nigel probably identifies with that,” Sked told the Parliament Street blog in 2014. “In many ways he’s a healthy version of Nigel,” he said. “He doesn’t smoke or drink and he does judo, though I don’t much like the idea of Nigel taking his shirt off.”

UKIP is currently the largest U.K. party in the European Parliament with 23 seats in the international body. It has the support of around 14 percent of voters, according to a BBC poll. When the last British Parliament ended, it had two members of parliament in the House of Lords, both defectors from the Conservative Party. Farage told the BBC on Wednesday that he had done his “absolute best” this election campaign.