Jeremy Corbyn is resisting calls to consider his position after Labour crashed to a humiliating defeat in the Copeland by-election.

MPs warned the party was on course for a "catastrophic" general election defeat after the Conservatives snatched the Cumbrian seat which had been held by Labour since 1935.

The Labour leader said the result was "very disappointing" but made clear that he was determined to carry on.

"I was elected to lead this party. I am proud to lead this party," he told reporters. "We will continue our campaigning work on the NHS, on social care, on housing."

Critics on the backbenches warned however that he had become an "obstacle" to victory and urged him to step down in the interests of the party.

Conservative Party chairman Sir Patrick McLoughlin hailed a "truly historic" victory for Tory candidate Trudy Harrison in the first gain for a governing party in a parliamentary by-election since 1982.

There was some consolation for the party in Stoke-on-Trent Central, where it saw off a concerted challenge from Ukip leader Paul Nuttall - albeit with a reduced majority.

But there was despair among Labour MPs at the defeat in Copeland in an area which has long been regarded as safe Labour territory.

John Woodcock, the MP for neighbouring Barrow-in-Furness, said the party was heading for disaster at the general election set for 2020.

"We are on course to a historic and catastrophic defeat and that will have very serious consequences for all of the communities that we represent," he told the BBC Radio 4 Today programme.

Senior Labour backbencher David Winnick said Mr Corbyn was an "obstacle" to victory and should consider his position.

"The party is faced with the problem of a leader who is simply not acceptable to a large number of people who would normally vote Labour," he told the Press Association.

"It is now entirely up to Jeremy and those close to him to decide what is best in the interests not simply of the party but the people we are in politics to represent."

There was however little appetite among MPs for a fresh leadership challenge after Mr Corbyn's crushing victory in last year's contest.

On a tumultuous night, Ms Harrison polled 13,748 votes to 11,601 for Labour's Gillian Troughton, increasing the Conservative vote share by more than 8% as Labour's dropped by nearly 5%.

Shadow chancellor John McDonnell, one of Mr Corbyn's closest allies, said there had been "unique" factors in Copeland which was heavily dependent on the Sellafield nuclear facility.

He said the party had had enough of "macho leaders" and that voters would respond to Mr Corbyn's "consensual" approach .

"Jeremy has a sense of duty. He will lead this party. He will rebuild it as a social movement, as we are doing now, and on that basis we will win the next election and he will be the prime minister," he told the Press Association.

He also hit out at Tony Blair and Lord Mandelson for high-profile interventions in the days before the by-elections.

"We can't have a circumstance again where a week before the by-election a former leader of our party attacks the party itself," he told the Today programme.

Ukip was also forced on to the defensive after Mr Nuttall's gamble of standing in Stoke Central failed to pay off, despite overwhelming support for Brexit in the city in last year's EU referendum.

After Gareth Snell held the seat for Labour with 7,853 votes to Mr Nuttall's 5,233, Ukip chairman Paul Oakden acknowledged it could be years before they managed to win a seat in Westminster.

"It took us 23-odd years to win a referendum to get Britain out of the European Union. It may take that long for us to get a seat in Westminster via a by-election," he told Today.

Former London mayor Ken Livingstone, a close Corbyn ally, blamed the party's declining poll ratings on disillusion with the previous Labour governments of Tony Blair and Gordon Brown. He dismissed Mr Corbyn's critics as "embittered old Blairites".

"If you look at the collapse in the vote, 20 years ago when Tony Blair won his first election, we got 58% of the vote in Copeland," Mr Livingstone told Sky News. "Two years ago at the last election that had collapsed down to about 4% more than we got yesterday.

"This isn't a decline that's happened under Jeremy. It's been happening for 20 years and you hear it from so many ordinary people on the streets saying, 'What did the last Labour government ever do for me?'

"If we are to turn this round, Labour MPs have got to stop undermining Jeremy and focus on the economy."

Labour MP John Spellar, who served as a minister under Mr Blair, responded to comments from Mr Corbyn's inner circle explaining the party's poor showing in the polls, by tweeting: "As Napoleon might have said after Waterloo."