Blaenau Gwent Labour members have selected their next parliamentary candidate despite protests over the use of an all-women shortlist.
Ms Jones is hoping to gain the local party's support
About 100 members attended the selection meeting at Ebbw Vale leisure centre to choose Maggie Jones, a Unison official, as their replacement for Llew Smith, who is retiring at the next election.
Ms Jones is originally from south Wales, but works in London for the public sector union.
The vote was organised by Welsh Labour centrally after the local party boycotted the selection procedure.
Up to 80 protestors gathered outside the meeting, jeering as members went in to cast their votes.
The gathering included current AM Peter Law, who has criticised the process, saying the constituency is being forced to take part in an experiment.
However, Ms Jones has said she now hopes to gain the support of all 700 local Labour members.
"I think I would have been a good candidate whether or not there was an all-women shortlist," she told BBC Wales.
"The fact that I was selected on this basis I think doesn't make any difference.
"I will be a good candidate for Blaenau Gwent and I have got to prove myself now and I hope to do that."
But Labour officials are insisting they will fight on, and are meeting on Friday night to decide their next move.
The Blaenau Gwent constituency is one of three in Wales with retiring MPs where Welsh Labour has decided to have all-women shortlists.
The move has been taken in an effort to boost the numbers of female Labour MPs.
Of the 34 Labour MPs in Wales, just four are women and the party wants to increase numbers.
Swansea East and Llanelli will go through the same process as Blaenau Gwent.
A warning for Labour from protesters
Last month, activists protested outside the shortlist meeting.
Labour must now wait to see what move Peter Law will make following the selection of Ms Jones.
There is a possibility that he could stand as an independent candidate against her.
The seat has been a Labour stronghold for decades, with previous incumbents including Michael Foot and Aneurin Bevan.
At the last election, Mr Smith had a majority of over 19,000.