Image source, PA

UKIP leader Nigel Farage has called the election result "perverse" and said there had been reports the postal vote was rigged. 

There were "stories of things that shouldn't have been happening" - including claims people turned up at polling stations with bundles of postal votes, he said. 

He said the issue was in part due to "big ethnic changes" in the area, and "some streets where no-one spoke English" but people were voting Labour. 

"They can't speak English. They've never heard of UKIP or the Conservative Party. They've never even heard of Jeremy Corbyn," he told BBC Radio 4's Today programme. 

Iain Watson
Political correspondent

On the eve of poll, Labour couldn't have looked more divided, with the shadow foreign secretary taking a completely different viewpoint from the party leader on an issue of national security. But Labour increased their share. 

Is this a vote of confidence in Jeremy Corbyn? It's possibly too soon to draw conclusions. UKIP ran a personal campaign against Mr Corybn, but it seems he is not the toxic figure they were expecting. But this was also not a typical by-election - it was a by-election fought on local messages. 

In his acceptance speech, Jim McMahon talked about himself, he talked about the town, he did not talk about his party leader. 

So I think to some extent there's a personal vote there, but the fact that the vote share went up quite so dramatically means that isn't the whole story. 

Labour has comfortably won the Oldham West and Royton by-election, with leader Jeremy Corbyn hailing it as a "vote of confidence" in his party. It followed less welcome headlines for Mr Corbyn, with alleged online bullying of MPs following the vote on UK air strikes in Syria. David Cameron said the operation in Syria would require "patience". The PM also said he did not expect a deal on his EU reforms at this month's European summit.

Arif Ansari
Politics correspondent, BBC North West Tonight

This was a surprise result for Labour, but an unexpectedly good one. 

Not only was Labour almost 11,000 votes ahead of UKIP, the party also increased its vote share. 

Only a fortnight ago some were predicting a shock defeat. Nobody anticipated a victory on this scale. 

Undoubtedly a large part of it must be down to the candidate Jim McMahon, the former council leader. He was recognised as the local candidate.

But UKIP tried to turn this into a referendum on Jeremy Corbyn, even branding him a "security risk". 

Clearly it failed and suggests he's not as politically toxic as his opponents wish. UKIP blames the postal vote and the number of Asian voters who use it. 

But that's the system the party is up against. UKIP's result was far worse than Heywood and Middleton and much more disappointing than it expected. And it leaves them struggling with a strategy to win seats from Labour in the north of England. 

We earlier said that Jim McMahon had won 17,322 votes - the Press Association has just issued a correction saying that the number was actually 17,209. 

This means that his share of the vote was 62.11%, not 62.27%. It is up 7.33% from the general election.

And it gives him a majority of 10,722.

The other results remain the same, and are as follows: 

UKIP - 6,487

Conservative - 2,596 

Liberal Democrat - 1,024

Green - 249

Monster Raving Loony - 141

Mr McMahon dismissed the UKIP leader's accusations.

"UKIP just need to understand that people have the right to vote for the party that best represents their interests," he said. 

"I can say with confidence that we represent every community in Oldham and every community came out and voted Labour."

Press Association

Labour's success "appears to have been secured with an effective postal vote operation", the Press Association reports.

But the UKIP leader Nigel Farage has claimed "serious questions need to be asked" about the result - which he described as "perverse".  

And here's some more from Labour leader Jeremy Corbyn. 

He said Mr McMahon "ran a great campaign, focusing on bringing jobs to Oldham and giving every child the best opportunities". 

To increase the share of the vote since the general election is "a vote of confidence" in Labour, Mr Corbyn claimed.

Mr McMahon, who is the leader of Oldham Council, said he was "delighted to be elected tonight".

Image source, Reuters

The new MP for Oldham West and Royton gives a thumbs up at Oldham's Civic Centre after the by-election result was announced. 

Mr McMahon said he felt that Michael Meacher was "watching over" him, and that he had been "so scared of letting Michael down". 

"I'm just glad that we have, together, delivered a result that Michael would be proud of," he said. 

Mr McMahon won 62.27% of the vote - up 7.49% from Labour's result at the 2015 general election.

Labour - 17,322

UKIP - 6,487

Conservative - 2,596 

Liberal Democrat - 1,024

Green - 249

Monster Raving Loony - 141

Jim McMahon retains the seat for Labour.

This Week

Polling expert John Curtice says if Labour end up with a majority of about 10,000 they will have a similar percentage lead over UKIP to the general election, given the lower turnout at this by-election.