Labour leadership contender Andy Burnham has warned it would be harder to unite the party following the leadership contest if "bad blood" and "negativity" was allowed to take over.
Mr Burnham said he found reported calls from Yvette Cooper's campaign to stand aside "disappointing", adding he thought it "quite strange" as he was in second place.
Jeremy Corbyn's two main rivals have been engaged in a bitter fight over who is best placed to stop the veteran left-winger's rise.
Supporters for Mr Burnham and Ms Cooper traded demands for each other to clear the path for the other amid claims of sexism and desperation.
Mr Burnham told BBC Radio 4's Today programme: "I praised the energy he (Mr Corbyn) has brought to the race, but then I set out yesterday the disagreements that I have with him on the economy, on Europe, on public services, that is exactly how a race like this should be conducted.
"If we let this bad blood as you describe it, the negativity take over, this party will be harder to unite coming out of this contest and that is what I am focused on.
"I want to win this contest and then unite this party."
Mr Burnham said he was "not giving anybody any advice as to how they should cast their second vote".
He added: "I think lectures from people at the top of the party as to how the membership should vote in this race, I don't think they go down particularly well."
Referring to warnings that Labour may be reduced to a party of angry protest under Mr Corbyn, Mr Burnham said "people may be overstating their criticisms, people don't know that".
He said: "This party needs to unite coming out of this race and I think some of the language now needs to be considered, more considered than it is because if you fuel this negativity and these warnings you just push these two camps apart."