An award-winning public health charity has parted company with its outspoken chief executive, three weeks after he attended an internal disciplinary hearing following a row over his leftwing political activities.

The UK Public Health Association said in a statement issued today that it had "agreed a parting of the ways" with John Nicholson, who is understood to have been made redundant following the closure last month of the charity's Manchester office, where he was based.

The charity will hope the agreement will draw a line under a three-month dispute between senior UKPHA board members and Mr Nicholson, whom they accused of undermining the charity's neutrality, partly though his private role as senior national officer of the Socialist Alliance.

The bitterness of that row was illustrated in leaked documents seen by SocietyGuardian.co.uk, in which UKPHA chairman Dr Geof Rayner accuses Mr Nicholson of disloyalty, misrepresenting the views of the charity, and of failing to develop the charity's website.

Mr Nicholson denied the allegations, and claimed that he was being politically victimised for his leftwing views by pro-government UKPHA council members who want "a much more cosy relationship with the Westminster government".

The statement issued today from UKPHA chair Geof Rayner pays fulsome tribute to Mr Nicholson, whom he said helped build up the 18-month-old charity and was effective in establishing for it a "significant" public profile.

It says: "While in his position the membership rose from around 600 to 1,500 and the charity was awarded the best new charity of the year award, and John was highly commended in charity chief executive of the year 2001."

Mr Nicholson has been a persistent critic of the government's social policy, frequently through the letters pages of the Guardian and professional magazines.

Both Mr Nicholson and Dr Rayner were unavailable for comment.