Analysis: Lockhart departure presents massive challenge for DUP and unionism

Within minutes of her resignation letter being published online on Monday, Carla Lockhart's photo and profile were stripped from the DUP webpage.

All traces of one of the party's most popular politicians were wiped away at breakneck speed.

The party she joined as a teenager wasted no time in moving on, issuing the shortest of statements regretting her decision to quit but making it clear such divisions in unionism only benefit Sinn Féin.

It was a parting swipe at its former Upper Bann MP in what was a bitter break-up.

Lockhart resigned from the DUP over its handling of the fallout of the Drumcree parading dispute.

Despite insisting she makes her own decisions, Lockharts's former colleagues remain convinced she is being manipulated by others.

They refuse to accept their one-time loyal MP could be fast-tracked out of the party without the influence of others.

Not so, says Lockhart, as she prepares to take her seat as an independent unionist MP at Westminster.

She leaves behind a party which has now just four MPs, falling from the high of 2017 when the DUP had 10 members of parliament.

It has also lost its only female MP and three of those left behind are in the twilight of their political careers.

Rebuilding the party's Westminister presence will be a massive challenge as unionism continues to splinter.

That fracture is now clearly illustrated on the green benches in the commons with no fewer than five different brands of unionism.

Two independents and three very different parties - the DUP, Ulster Unionist Party (UUP) and Traditional Unionist Voice (TUV).

No wonder the cries for unionist unity has grown louder in recent weeks.

So much so that alongside her resignation letter Lockhart published her own vision for the future of unionism.

The eight-page document set out her key principles and action plan for unity.

It was clearly timed and aimed at those who would accuse her of further dividing unionism with her departure from the DUP.

She wanted to have a positive to off set any negative narratives.

Her decision to remain as an independent MP and ignore any advances from the TUV was also well calculated.

As the only DUP MP elected with the support of TUV votes, Lockhart was in a unique position.

Upper Bann was the only constituency where the TUV opted against fielding a candidate in the last Westminster election.

As a result Carla Lockhart has a wide support base which she will hope to count on next time around and remaining as an independent will help her cause.

The DUP is also less likely to run a candidate against her as an independent and avoid the risk of splitting the unionist vote and possibly handing the seat to Sinn Féin.

Before then there is an assembly election to be fought in May and the new independent MP for Upper Bann will be under pressure to endorse candidates.

As the party which now shares her political outlook, the TUV will be hopeful of securing her support.