Alex Attwood gives his support to Margaret Ritchie
The SDLP's Alex Attwood has said he supports Margaret Ritchie as leader.
On Tuesday, the party's deputy leader Patsy McGlone announced he would be launching a leadership challenge.
Ms Ritchie has been in the post less than two years but recent poor election results have prompted growing discontent within the party.
Mr Attwood commended Margaret Ritchie's record as leader and said others were judging her on a few media performances.
He said "she sticks to her position, stays the course", and that she was an "electoral asset in her own constituency".
"Maybe people who don't have the electoral strength in their own constituency should be careful about thinking they can do better than Margaret Ritchie," the environment minister warned.
"Margaret has been tested in a lot of places and came out looking good. Would they come out looking as good?"
When asked about Patsy McGlone, Mr Attwood said he would not be commenting on other candidates.
The SDLP MLA for South Belfast, Conall McDevitt said: "This is a matter for debate in September.
"August is not the best month to be engaging in a big debate about the SDLP's future. This is not just about the leadership, but about the future direction of the party."
Mr McGlone's confirmation that he would stand follows weeks of speculation.
He said he had been encouraged to do so by friends and colleagues who shared his belief that "now is the time for change."
The Mid Ulster MLA said: "I am proud of my Irishness and proud to offer myself as leader of a party which represents an Irishness of inclusivity, regardless of race, colour or creed.
"These core values, articulated by John Hume and Seamus Mallon, are precisely what attracted me to the SDLP in the first place.
"The SDLP has revolutionised Irish politics. The founding principles of the party are as relevant today as they were during the civil rights campaign.
"The unity of the people of Ireland, a unity built on trust, along with practical social democracy - being there for people through the good and bad times - lie at the heart of every SDLP member and supporter.
"The way forward for us needs three strategic elements: strong leadership, clarity of message and radically improved grassroots organisation. "
Ms Ritchie has already made clear she would contest any leadership challenge at the party's annual conference which take place this November.
"Anyone in the parliamentary assembly group is free to put their name forward if they get the nominations," she said last week.
"But at the end of the day, I am the leader."
There has been growing discontent in SDLP ranks since the party lost two assembly seats in May's elections.
Ms Ritchie replaced Mark Durkan as leader at the start of 2010.
She defeated the South Belfast MP Alasdair McDonnell by 35 votes.
During this spring's Assembly election campaign, Ms Ritchie's style and media performances came in for some criticism.
The divide between Ms Ritchie and her deputy Mr McGlone became clear when she passed him over for a ministerial job and he refused her offer of a Stormont committee chairmanship.