Jeremy Corbyn will make a fresh appeal to Brexit voters as part of the left-winger's New Year message, to be released on Friday morning (30 December).

Corbyn, who was re-elected Labour leader with an increased majority in September, is expected to argue that the Leave campaign won the referendum because of disillusionment with the political class and the EU.

"2016 will be defined in history by the referendum on our EU membership", he will say. "People didn't trust politicians and they didn't trust the EU.

"I understand that. I've spent over 40 years in politics campaigning for a better way of doing things, standing up for people, taking on the establishment, and opposing decisions that would make us worse off."

The Labour leader will also argue that decisions made in Westminster are "making people's lives harder", referencing the social care system in England and Wales, low pay and zero-hours contracts.

Corbyn will add: "Labour was founded to stand up for people and we founded the institutions that do that day in, and day out, like our NHS. We are the party that listens to you and makes Britain better. Let's do that, together, in 2017."

The comments will come after Corbyn was dealt another blow, with Jamie Reed's resignation as Labour MP for the Cumbrian seat of Copeland. Reed, a critic of Corbyn, secured a majority of just over 2,500 votes at the general election.

The by-election for the north of England constituency will be an early test in 2017 for Corbyn. The city region mayoral elections of 2017, including Greater Manchester, West Midlands and Greater Liverpool, will provide another marker for Labour's popularity in May.

But the political year is expected to be dominated by the UK's split from the EU. Theresa May has promised to invoke Article 50, the mechanism to split from the bloc, by the end of March 2017.

The Supreme Court will rule in January over whether MPs need to have a vote on triggering the mechanism. Labour have promised not to block a Brexit, but the party has said they will seek an amendment to an Article 50 bill if the government does not unveil a "meaningful" plan.

"A Brexit that protects the bankers in the City and continues to give corporate handouts to the biggest companies is not good enough," Corbyn will say.

The latest national opinion poll from Opinium for The Observer, of 2,000 voters between 13 and 16 December, put the Conservatives seven points ahead of Labour (38% versus 31%).