Former Liberal Democrat MP Lembit Opik described the South Shields result as "appalling" and demanded a "credible explanation from Nick Clegg regarding the recovery strategy".
The Lib Dems secured just 352 votes.
Mr Opik lost his Montgomeryshire seat in 2010.
.@davidlhennigan fair point but let's be honest: appalling result. Veteran members deserve to know how this electoral crisis will be fixed
South Shields by-election gave 1.4% for Lib Dems. I ask for a credible explanation from Nick Clegg regarding the recovery strategy.
More top news
Brian Cullinan's error led to La La Land being mistakenly announced as the Best Picture at the Oscars.
The Food Standards Agency said the product can be returned "from where it was bought for a full refund."
The car giant said it would cut 1,160 jobs at the plant in Bridgend.