The Liberal Democrat candidate in Stockton South has endorsed his Labour opponent, urging the electorate to vote tactically with less than 24 hours until polls open.

Brendan Devlin said polling shows the constituency is a battle between Labour and the Conservatives, and called on voters to “choose wisely”.

Mr Devlin described Labour rival Dr Paul Williams as honest and sincere, prompting Dr Williams to thank him for the “personal endorsement”.

Mr Devlin tweeted: “Polling shows that Stockton South is a Lab/Cons battle. I cannot and do not endorse either Party or their leadership. But I have met Paul; he’s an honest, sincere man, and if I needed help, I know he’s reliable and committed to social justice. And he turns up to hustings…

“LiberalDemocrats are a party of reason motivated by human dignity and concern for our country; in these final moments of this election, I urge all voters to choose wisely with those thoughts in their minds.”

He added: “To be crystal clear: vote tactically for someone who cares about the NHS and social care. Those are important in Stockton South.”

Dr Williams, who has been the MP in Stockton South since 2017, tweeted: “Thank you for the personal endorsement @BrendanDevlin50.

“You’ve been able to put party and personal interest to one side in favour of the national interest.

“I’ve grown to know you over the last 5/6 weeks as a truly kind and honourable man.”

The Vote For A Final Say campaign has published a list of 20 third-placed Liberal Democrat and Labour candidates, which included Mr Devlin, who they say risk guaranteeing a Tory parliamentary majority.

A Liberal Democrat spokeswoman said: “Brendan Devlin has clearly acted independently and locally. Across the country the best way of ensuring that Brexit is stopped is to vote Liberal Democrat. We are working for every Liberal Democrat vote to stop Boris and stop Brexit.”

A Labour Party spokesman said: “Only a Labour government can stop Boris Johnson selling out our NHS and give people the final say on Brexit.”

A Tory spokeswoman said: “This just shows that a vote for any other party than the Conservatives will put Jeremy Corbyn in Downing Street, propped up by Nicola Sturgeon and smaller parties.

“That would mean the nightmare scenario of wasting the whole of next year gridlocked in two more chaotic referendums, and a wrecking ball taken to our economy.

“Only a vote for the Conservatives will get Brexit done so we can move on and unleash the potential of our whole country.”