Norton Rose’s former head of competition Martin Coleman has left the firm to become a non-executive director for the Competition and Markets Authority (CMA), The Lawyer can reveal.

Coleman ran in the election for chair of the Norton Rose LLP in February 2012, two weeks after the firm had already announced it had chosen Stephen Parish to be re-elected for the role.

However, owing to the unease among partners that the election was an usher-in for Parish, CEO Peter Martyr extended the deadline by a week to allow other candidates to stand.

Parish was re-elected to the role and remains the chair of the UK LLP. He has held the post since 2009.

Coleman was also one of a number of candidates who went for the role when Parish was first elected in 2009. He was a Labour leader of Brent Council in the 1980s and came a close third in Northampton South in the 1983 general election.

At the time, a source said: “Martin’s the sort of person who’d take a stand on principle if he felt that something was being pushed through or was undemocratic.”

Coleman left Norton Rose last month according to his Linkedin profile. He was appointed non-executive director of the CMA on 1 October, where he will be responsible for policy and strategic direction of the competition watchdog.

In August the firm was hit with exits from its merger partner in Australia, Henry Davis York. Five partners in the restructuring and banking and finance team left the firm to join independent firm Corrs Chambers Westgarth’s Sydney office.

Before that, four Perth-based partners left to launch Pinsent Masons’ third Australian office in Perth.

The firm committed itself to merging with Australian firm Henry Davis York after partners overwhelming voted in favour of the union in June.

Recent years have seen the firm acquire and merge with a series of firms, including with South African firm Deneys Reitz in 2010, Bull Housser in Vancouver in September last year, and more recently, its merger with Chadbourne & Parke which went live in June following a number of alleged delays over client conflicts, which global chief executive Peter Martyr later denied.

In London, Norton Rose Fulbright also lost international disputes partner Deborah Ruff, shortly after the completion of its merger with Chadbourne & Parke in July. Ruff will join US firm Pillsbury Winthrop Shaw Pittman to launch a London dispute practice and lead the firm’s global arbitration practice.

Norton Rose Fulbright and Coleman were contacted for comment.