The SDLP's head of campaigns is to quit the job less than a year after taking up the high-profile position.
The party was shocked to hear that Tanya McCamphill, who was a key appointee by leader Colum Eastwood, is leaving the post.
Ms McCamphill previously worked for the Scottish National Party.
She was regarded as an important strategist in the SDLP's efforts to strengthen its base within the nationalist community and become competitive electorally again with Sinn Fein.
Her experience in Scotland meant she brought valuable skills to the SDLP.
Ms McCamphill last night declined to give reasons for her departure but stressed her allegiance to the party.
She said: "I was delighted to take the post with the SDLP as head of campaigns last June for one year. It was a privilege to work for the party.
"I will remain a loyal SDLP party member, a dedicated activist and supporter of the SDLP leadership."
Last month, Mr Eastwood refused to rule out the SDLP standing aside for Fianna Fail to organise in Northern Ireland.
The two parties have been involved in talks about that possibility.
The loss of its three MPs last June has placed the SDLP under increasing financial pressure.
The party is moving from its Ormeau Road headquarters which it has been forced to sell.
The SDLP lost more than £100,000 in payments from Westminster after Alasdair McDonnell, Margaret Ritchie and Mark Durkan were unseated.
It already operated on a very tight budget.
Following the SDLP's Westminster wipeout serious questions have been raised about its future. Some members and elected representatives want to see it step aside swiftly to allow Fianna Fail to organise here before next year's council elections.
But there is opposition to this among young members and Belfast activists in particular.