Jeremy Corbyn's Labour MP critics must not deliberatly move against him should he be elected party leader on Saturday, Diane Abbott has warned.
The leftwing candidate to replace Ed Miliband looks set to secure a surprise victory when the result of the months long contest is announced this weekend.
Corbyn scraped into the race at the last minute after just receiving the required 35 nominations from fellow Labour MPs.
And several senior Labour MPs including leadership rivals Yvette Cooper and Liz Kendall have said they would refuse to serve in Corbyn's shadow cabinet due to fundamental disagreements over policy.
Abbott, a leading supporter of Corbyn told the BBC's Daily Politics on Monday that MPs should not ignore the wishes of party members and those who voted in the contest.
"I think the important thing now is that whoever wins, the Parliamentary Labour Party is prepared to give them a fair wind. The party will not understand if the PLP acts to deliberately disrupt a new leader, she said.
Shadow education secretary Tristram Hunt, who has said he would refuse to serve Corbyns team, said party unity was important and that Corbyn should be treated fairly.
However he said he was within his rights to go ahead with setting up the new Common Good internal Labour group which he said aims to help the "political renewal" of the centre and right of the party.
"It's only right when we think about pluralism progressive the non-statist tradition in the Labour Party, actually we begin to renew our ideas," he said.
Last month, shadow business secretary Chuka Umunna denied the new group was part of a "resistance" movement against Corbyn.