Senator Humphries was dumped from the top spot on the Liberals' ACT Senate ticket, in favour of former Canberra Liberals leader Zed Seselja.
A top level Liberal Party meeting will consider a motion to have the result set aside because of concerns that many members were denied a vote.
Senator Humphries was asked on Monday whether he would renominate if the challenge was successful and he said he did not intend to.
But he now says if the preselection result is set aside he will nominate again.
He says he has received many emails, letters and phone calls from party members deeply upset by the preselection process.
"More disturbingly, I have also received news from many party members who were refused the right to vote in the ballot on Saturday," he said.
"These were members who had previously been informed by the ACT Division of the Party that they were eligible voting preselectors, but whose right to vote was "withdrawn" on the day.
"I am saddened and shocked that the preselection has been so badly conducted that such treatment is meted out to party members."
Former Liberal Party president Gary Kent is running the campaign to have Saturday's preselection result set aside.
He says he is pleased Senator Humphries will stand again.
"I haven't discussed this at all with Gary. I'm not really surprised. I think that it's become increasingly clear that the last preselection was incredibly unfair," he said.
"I'm pleased that Gary's indicated that if there's another preselection he will contest. I think he would have formed the view that the next one will be a lot better than the last one."
Mr Kent says party members simply want a fair preselection.
"It's not about Gary or Zed or anybody else. It's about wanting the members to have their say. And if Gary or Zed or anybody else wins the next preselection, if there is one, they will be happy that it's been done fairly," he said.