Carla Lockhart has stood down as party officer for the Democratic Unionist Party (DUP) as a difference of opinion over how to deal with the fallout of the Drumcree dispute persists within the party.

As an officer she belonged to a small, decision-making committee within the DUP. "I believe in standing true to my principles.

I cannot continue to be part of the team that decide on the direction and strategy discussions of the party, whilst clearly having concerns about that," she said in a statement.

DUP leader Gavin Robinson said "she remains a key part of our team" and that he "would rather that she hadn't" quit her party officer role.

Lockhart has been growing into one of the highest profile DUP representatives for a number of years, but her profile has been raised significantly since the reignition of the Drumcree dispute.

As Upper Bann MP, the Portadown-based dispute has played out within her constituency. What is the Garvaghy Road dispute all about?

Lockhart previously said her constituents were angry with First Minister Michelle O'Neill over her role in the Garvaghy Road protests and said it "cannot be business as usual" at Stormont.

She said the DUP had it "within its gift to remove" O'Neill as Northern Ireland's first minister.

This would mean removing Deputy First Minister Emma Little-Pengelly from her role, as the two ministers share an office and cannot function without one another - which the party has not done.

In a public statement on Thursday night, Lockhart said she had not intended to publicly share news of her resignation, "but it appears someone internally within the DUP grouping leaked this to the media".

"I have already highlighted my concerns publicly about the need for profound consequences [over Drumcree]," she added.

"Whilst the party, has been clear that all options are still on the table, I believe that the speed of these needs to be quicker." She said her "focus will always be on representing Upper Bann" and that she "will continue to do that without favour".

Education Minister and DUP MLA Paul Givan described Lockhart's decision as "disappointing" but said he welcomes her remaining within the party.

"Carla bleeds DUP, like I do," he said on Good Morning Ulster adding: "she is a valued member of our party and I know she will continue to make a contribution".

Speaking on BBC's The View Robinson said Lockhart spoke to him directly about quitting as a party officer and that, while "sorry" to see her go, he said "it's not a disaster" for him.

Asked could this be the first move in her leaving the party altogether, he answered: "I hope it's not." Robinson called Lockhart a "great constituency MP" and "somebody who's been in the middle of the difficulties over the last four or five weeks".

"She's somebody for whom I've not only supported but I have stood over her position when she's reflecting the anger of those within her constituency… And I've said that she is right to do so." Robinson said, however, the DUP had reached a democratic decision on how to deal with the fallout of Drumcree, and suggested collapsing the executive was not the will of the majority.

"The thing... we as a party has focused on over the last number of weeks is why should we punish everyone in Northern Ireland when actually we should be punishing those who broke the law?" He added: "We have considered all options and we keep all options on the table." Robinson said the DUP "had important conversations" on Thursday that he wished Lockhart "had been a part of". "She wasn't, that's okay.

We've had discussions in our party and we've agreed our position." Traditional Unionist Voice (TUV) assembly member Timothy Gaston said he has "no idea" if Lockhart has had discussions about joining the TUV.

"I have no idea... that would be above my pay grade," he told the BBC's Nolan Show "Carla will make her own decisions and I have every faith that Carla will do what's right, because that is what Carla has done till now," Gaston said. "She has spoke out.

She is fed up with the word salads from other people." He added that it is "up to Carla what her next steps are".

Lockhart has been one of the DUP's most vocal supporters of the Orange Order's efforts to march along the mainly-nationalist Garvaghy Road in Portadown.

The dispute returned to the headlines earlier this year after a court challenge overturned a Parades Commission decision restricting the parade. The commission subsequently allowed the march to proceed under stricter conditions, but the planned procession was prevented from taking place after residents blocked the route.

The debate intensified when elected nationalist MLAs, including the first minister, joined protesters on the road. Lockhart publicly backed the Orange Order's position, arguing that its members should be allowed to complete the traditional route.

At a rally in Portadown on 30 September, she said, "there'll be no capitulation on the part of the Portadown district." She also criticised a proposed resolution document put forward by Northern Ireland Secretary Sir Chris Bryant, describing it as "not acceptable".

The document was part of efforts to resolve the dispute between the Orange Order and the Garvaghy Road Residents' Coalition.

Northern Ireland Secretary Sir Chris Bryant banned the Orange Order parade at Drumcree on 9 October. Sir Chris said the Police Service of Northern Ireland's chief constable advised him "it would not be possible to enable the procession to happen without a major intervention which would carry an unacceptable risk of serious injury, disorder and a wider contagion effect across Northern Ireland".

Following the ban, Lockhart called for a tougher response from the DUP over O'Neill's involvement in the protests.

Speaking the day after the parade ban outside Drumcree Church she said her constituents were angry with O'Neill, accusing her of "thumbing her nose at unionism and at the Orange Order and at this community".

Lockhart said: "It cannot be business as usual at Stormont", adding that the DUP must take action against O'Neill.

DUP leader Gavin Robinson said that Lockhart "is right that the options are there", but stopped short of suggesting his party may collapse the executive.

Robinson also called on the chief constable to "be very open" in telling the public "what was the threat that he perceived" when he asked the secretary of state to review the Parades Commission's determination.

She has been on resignation watch for weeks and now it appears Carla Lockhart has taken the first big step towards the DUP exit door.

The Upper Bann MP could no longer be part of a leadership team which she believed was leading the party in the wrong direction.

So strained is the relationship that she took a swipe at those within the "DUP grouping" who leaked her decision to the press.

While there was no hint in her late night statement that she was planning to quit the party sources within the DUP believe it is now a question of when and not if she will walk away.

Despite sharing a packet of sweets with the party leader Gavin Robinson on the plane back from London on Thursday it is clear their relationship has turned sour.

Robinson has repeatedly knocked back her demands to "sack" Michelle O'Neill as first minister by removing Emma Little-Pengelly as deputy first minister. Frustrated by the lack of action, Lockhart has been left with few options. But will it be a speedy departure or a long goodbye?

We may get a hint of her next move when she addresses a rally in support of the Portadown Orangemen in the town on Saturday.