Nigel Farage called a ‘disgrace’ after blaming Germany’s open-door policy for the Berlin attack

Nigel Farage, the former outspoken leader of the populist U.K. Independence Party, has apparently gotten himself into trouble for calling out German Chancellor Angela Merkel on her open-door immigration policy following the deadly truck attack in Berlin earlier this week.

After a driver plowed into a Berlin Christmas market, killing 12 people and injuring nearly 50 more, and the Islamic State claimed responsibility for the assault, Farage took to Twitter to rip Merkel's support of open borders — a position that has been praised by her international counterparts but has created quite a bit of consternation in Europe.

In response to Farage's comment, Brendan Cox, husband to slain British lawmaker Jo Cox, who was killed by a white supremacist, said it is a "slippery slope" to cast blame on politicians for the work of extremists.

Farage offered a longer response to Cox during an interview on London's LBC Radio Tuesday:

Well of course he would know more about extremists than me. Mr. Cox, he backs organizations like Hope Not Hate, who masquerade as being lovely and peaceful but actually pursue violent and very undemocratic means.

And I'm sorry, Mr. Cox, it is time people started to take responsibility for what's happened. Mrs. Merkel had directly caused a whole number of social and terrorist problems in Germany, it's about time we confronted that truth.

Some were not very impressed with Farage's remarks, including Jack Dromey, a Labour lawmaker, who took to Twitter to call the former UKIP leader "a disgrace to our country."

In addition, Hope Not Hate, a charity that has frequently pushed back against the UKIP's populist bent, issued a statement on Farage's "outrageous attack" on the group, Cox "and by association on everyone who believed in Hope Not Hate."

"Our lawyer has just sent Farage a letter demanding he retracts and publicly apologizes or we will begin legal proceedings against him," the group said in a statement.