Alex Cunningham, the MP for Stockton North, was speaking after Jeremy Corbyn was re-elected leader of the Labour Party with a bigger mandate than before, winning 62% of the vote.
The leadership contest came after a mass walkout from the shadow cabinet and a 172-40 vote of no confidence in Mr Corbyn's leadership by MPs.
Jeremy Corbyn said on his victory: "I will do everything I can to repay the trust and support, to bring our party together, to make it an engine of progress for our country and the people that depend on the Labour Party to protect their interests, and win power to deliver real change in this country.
""We have much more in common than that which divides us.
"As far as I'm concerned, let's wipe that slate clean from today and get on with the work we have got to do as a party together."
Alex Cunningham said he was "disappointed" with the result, but added there was a "chance" the party could win in 2020.
Speaking on Premier Christian Radio he said: "My prayer for the party is for unity, first and foremost.
"I think we need to come together. There was a good strong message from Jeremy Corbyn today, he wants to wipe the slate clean.
"I'm hoping that my colleagues will all respond positively and realise that this is about fighting the Tories, not about fighting each other."
Listen to Premier's Aaron James speaking to Alex Cunningham: