Kim Leadbeater’s surprise triumph in the West Yorkshire seat has highlighted the “critical battle” between “decency and integrity (...) verus half truths and manipulation”, according to Sir Keir.
Ms Leadbeater will take her seat in Parliament - holding the constituency previously held by her sister and murdered MP Jo Cox - with a majority of just 323 votes over second placed Conservative candidate Ryan Stephenson, whom many had expected to win.
The win for Labour has ended - at least temporarily - the speculation in some quarters about the leadership of the Labour Party following its loss of the Hartlepool by-election in May.
Speaking to journalists following his visit to the constituency to celebrate Ms Leadbeater’s victory, Sir Keir said: “What we saw here was that those core values that Kim embodies - that are the values of the Labour Party - in the end bring people together and are very persuasive.
"Those core values of more in common and bringing people together, of decency and integrity versus misinformation and manipulation, untruths and half truths.”
He went on: “I think there’s a lot to learn from Batley and Spen on politics and the critical battle between decency and integrity, honesty and truth versus misinformation untruths, half truths and manipulation.”
When asked specifically what could be learned from the race, Sir Keir referred back to Ms Cox’s maiden speech, and the “core and central lesson” it identified, “that whatever differences of opinion we may have, we do have more in common with each other than we have that separates us.”
“That’s why it's very important when we’re making arguments in red wall seats or any other seats that we are rooted in our communities, we are rooted in those values and we share the priorities of those that we want to vote for us,” Sir Keir said.
The campaign for the Batley and Spen seat was bitter and tense at times, and in her acceptance speech, Ms Leadbeater thanked the police “who, sadly, I have needed more than ever over the last few weeks”.
There were reported clashes between Mr Galloway’s Workers Party and Labour supporters as they battled for votes in the constituency’s Asian communities.
At one point, Ms Leadbeater was confronted by a man who challenged her over the situation in Kashmir and her stance on LGBT education in schools amid what he said were concerns from Muslim parents.
There were also allegations from Labour activists that they were pelted with eggs and kicked in the head.