This is how Jeremy Corbyn's team believes he can still become UK prime minister

LONDON - "I think two years ago we would have been surprised if we had been in this event at all," Jeremy Corbyn told a room full of journalists at a Christmas party in his parliamentary offices last night.

He is not the only one to have been surprised. Few expected the little known left-wing MP to even make it onto the ballot paper for Labour leader in 2015, let alone win two leadership elections on the trot.

Yet two years on and Corbyn's takeover of the Labour party is all but complete, with even his biggest opponents within the party now resigned to the fact that he will take them into the next general election.

The prospects for that election look bleak. The latest YouGov poll puts the party on just 25%, their lowest level in opposition since the early eighties. In recent weeks they have suffered two humiliating results in the Sleaford and Richmond by-elections, pushed into fourth place in one and even losing their deposit in the other.

Yet the mood among Corbyn's team is not as bleak as these facts suggest it should be. Flush with cash from the last leadership election, Corbyn has a bigger and more professional team at his disposal than ever before.

In recent weeks Corbyn has brought in James Schneider, a former Momentum organiser and member of his last successful leadership campaign, as his head of strategic communications. Schneider is controversial among some in the party, but is a highly effective operator who is held in high regard by many of the journalists who covered the last leadership election. He has been joined by David Prescott, son of the former Labour deputy prime minister, who has been brought in to work on Corbyn's speeches and his appearances at Prime Minister's Questions.

Corbyn's performances in the latter have noticeably improved, with the Labour leader taking a more focused and topic-driven approach to questioning the prime minister. Although he is unlikely to ever receive rave reviews from the press, he has been widely judged to have won several of his recent encounters with Theresa May.

The rest of Corbyn's team are also sharpening up their act. His chief spinner Seumas Milne has been accused in the past by some journalists of being aloof and difficult to reach, but he was on noticeably good form at Corbyn's Christmas drinks last night, chatting and joking with journalists from all wings of the press.

Not everyone is convinced by the transformation.

Asked whether they had noticed any improvements in Corbyn's operation, one former Miliband aide told Business Insider that things had "got much worse" in recent months.

Far from turning things around, public opinion of Corbyn has nosedived from the already subterranean levels seen before the leadership contest began. The parliamentary party, which has been relatively quiet for the past few months, is also getting restless again. Shortly before Corbyn's rinks began, Labour MPs met in another part of Parliament to voice their anger at the new chief whip Nick Brown's decision to speak at a Momentum event where members called for the mandatory re-selection of all Labour MPs.

Yet there are still reasons for Corbyn's team to feel optimistic.

While relatively popular at the moment, the prime minister faces an oncoming constitutional and political crisis the like of which has never been seen before. Once the starting gun is fired on Brexit negotiations early next year, she will face a series of seemingly intractable challenged on everything from trade to the territorial integrity of the United Kingdom.

Her behaviour in recent weeks, where she has been engaged in a bizarre dispute over a pair of leather trousers and a far more serious dispute with her foreign secretary, does not suggest that she is equal to the task of solving these challenges.

The Labour party, under the direction of shadow Brexit secretary Keir Starmer has already won one parliamentary victory over the government on Brexit.

If Corbyn's newly beefed-up team can hold it together, then there will be many more opportunities, both inside and outside Parliament, for them to become a far more effective and politically successful opposition. The opportunities for Labour to improve their position are clear. The opportunities for the Conservatives to fall backwards are equally clear. 

Of course none of this means that Corbyn is heading for Downing Street any time soon. Those around the Labour leader say they still expect May to call a snap election within the coming year. If that were to happen then the Labour party would be overwhelming favourites to face a crushing and possibly existential defeat.

But if Theresa May sticks to her word and does not call an election until 2020, then Corbyn's team still believe that Labour can recover significantly from the bleak position they currently occupy. As Corbyn heads into the Christmas holiday there are at least some reasons for the apparent festive cheer seen last night within the Labour leaders' office.