UK Conservative Party Chairman Oliver Dowden announced Friday on Twitter that he had resigned with immediate effect after the ruling party lost two by-elections.

"Yesterday's parliamentary by-elections are the latest in a run of very poor results for our party. Our supporters are distressed and disappointed by recent events, and I share their feelings," Dowden said in a resignation letter to Prime Minister Boris Johnson.

 He said "someone needs to take responsibility," and it would not be right for him to remain in office.

The Conservatives suffered two crushing by-election defeats, including losing the Tiverton and Honiton seat to the centrist Liberal Democrats in a deeply Conservative part of southwest England.

And the main opposition Labour Party regained the Wakefield constituency in northern England.

In response to the defeats, Johnson on Friday said he would "listen" to voters and "keep on."

"It's absolutely true that we've had some tough by-election results, I think it was a reflection of a lot of things, but we have to recognize that voters are going through a tough time at the moment," he said.