The former Australian Defence Member of 31 years urged for calm within the party amid the ongoing leadership speculation targeting Prime Minister Tony Abbott.
In an email sent to colleagues, Mr Nikolic said he wrote “more in sadness that (sic) criticism” in the wake of Mr Abbott's decision to nominate Prince Philip for a knighthood.
“In recent days, media reports suggest we are showing signs of the same sort of ill-disciplined introspection that characterised the Rudd-Gillard-Greens Coalition - the very same behaviours that the Australian people comprehensively rejected in September 2013,” he said.
“Recall for a moment how absolutely fed up with your constituents were with government that focussed on itself rather than the needs of our communities.
“My electorate still feels like that and I hate the thought they might tar us with the same brush.”
Mr Nikolic urged his colleagues to "knuckle down, re-focus on what's important and not become the rabble we defeated".
The was also made by the Prime Minister during his adddress to the National Press Club on Monday.
Addressing questions on leadership, Mr Abbott said he still had the confidence of the party room and pointed to the Rudd-Gillard-Rudd governments.
"We were elected in 2013 because the Australian people rejected chaos," he said.
"That's why we were elected, because the Australian people rejected chaos.
"And we are not going to take them back to that chaos."
Palmer United Party leader Clive Palmer also weighed in, saying Australia did not want a return to the Gillard-Rudd era of persistent leadership tensions.
"The Liberal Party needs to resolve its matter of leadership immediately," he said.
‘He'll be lucky to make it to the end of the week’
His email follows comment by Wayne Swan, who urged the Coalition to avoid a spill.
Speaking on the ABC’s Q and A program on Monday, the former Federal Treasurer said it was likely that Mr Abbott would be ousted before the budget, but advised caution.
“I've seen a leadership challenge or two, and I think changing leaders is really risky,” he said.
Leadership speculation dominated discussion among the federal politicians on the program, with independent Senator Jacqui Lambie saying Mr Abbott would be ousted before the weekend.
The former Palmer United Party Senator said he had failed to listen to cross benchers, citing it as a failure.
“He won't make it,” she said.
“He won't make it to the end. He'll be lucky to make it to the end of the week.”
Nationals MP Barnaby Joyce however said the Coalition would “get through this”.