MYSTERY surrounds the decision of a long-serving and leading Labour councillor to quit the party to become an Independent member on the eve of a crucial vote.

Councillor Paul Baldwin, who served as the 135th Mayor of Darlington in 2012 raising more than £6,000 for St Teresa’s Hospice and the Great North Air Ambulance, has notified Darlington Borough Council he will continue serving residents in the Cockerton ward as an Independent member.

His decision comes almost 25 years after first being elected to the authority for Labour, which he joined while active in trade unions and eight months after seeing the party lose control of the authority for the first time in decades.

Cllr Baldwin, who stepped down from his post as cabinet member for community protection on the authority in 2003 saying “family considerations take precedence”, was unavailable for comment.

The authority’s Labour Party declined to comment on the former planning committee chairman’s decision or on suggestions that it could be related to controversial changes to the forthcoming Local Plan, which will form a blueprint for the borough until 2036.

The Local Plan was developed under the previous Labour administration but paused in July by the Conservatives in order for it to be re-evaluated.

The revised version has attracted controversy from some residents and the Green Party, which produced its own study on the proposed developments following what it said were “significant concerns from residents about overdevelopment of the town, particularly on greenfield sites, and the irreversible damage this was doing”. At a recent council meeting councillors commented the Local Plan, which is set to be pushed forward this week, had become “very political”.

However, party insiders say the losses Labour suffered at the polls have shaken even long-standing activists.

Darlington MP Peter Gibson said: “It is clear that the strengthening Conservatives in Darlington and the wider Tees Valley have significantly impacted Labour locally, their loss of seats in the General Election can have only weakened them further. Resignations from the rudderless group on the council is simply a sign of more Labour disarray in Darlington.”

Outside of politics, Cllr Baldwin, whose wife Kim acted as consort during his year as mayor, has worked for BT and taught physics at Sedgefield Community College.