Reuters
Farage told BBC Radio 4's Today programme that "big ethnic changes" in Oldham West and Royton led to areas where "some streets where no-one spoke English" so less people were inclined to vote UKIP.
"They can't speak English. They've never heard of UKIP or the Conservative Party. They've never even heard of Jeremy Corbyn," he said on the radio.
He said claims of vote rigging was also rife and this could have swayed the end result. He highlighted there were "stories of things that shouldn't have been happening," and included claims of people "turning up to polling stations with bundles of postal votes."
"Effectively the electoral process is now dead," he said in the interview.
Earlier this morning he tweeted those same thoughts:
Evidence from an impeccable source that today's postal voting was bent.
- Nigel Farage (@Nigel_Farage) December 4, 2015As a veteran of over thirty by-elections I have never seen such a perverse result. Serious questions need to be asked.
- Nigel Farage (@Nigel_Farage) December 4, 2015Jim McMahon claimed a massive 62% of the vote share, which is actually higher than that at the general election.
McMahon also secured a 10,835 majority from UKIP's John Bickley, who was tipped as Labour's strongest contender for the so-called Labour "safe seat" which the leftwing party has held for the last 45 years.
The by-election was triggered after long-serving Labour MP Michael Meacher died earlier this year. In May's general election, he won the seat by 14,000 more votes than UKIP's candidate.
This is a break down of the results. The number is the total votes and the percentage in brackets is the vote share):
- (Labour) Jim McMahon - 17,209 (62.11%)
- (UKIP) John Bickley - 6,487 (23.41%)
- (Conservative) James Daly - 2,596 (9.37%)
- (Liberal Democrat) Jane Brophy - 1,024 (3.70%)
- (Green Party) Simeon Hart - 249 (0.90%)
- (Monster Raving Loony) Sir Oink A-Lot &mdash 141 (0.51%)