The leader of the Liberal Democrat group at Milton Keynes City Council died at the party’s annual conference on Saturday evening.
Councillor Robin Bradburn had also served as the local authority’s deputy leader since 2021.
His wife Marie is the mayor of Milton Keynes, and his daughter Kerrie is also a city councillor.
A minute’s silence was held in honour of Cllr Bradburn at the Liberal Democrat conference on Sunday.
Council leader Peter Marland said: ‘Cllr Robin Bradburn was a role model of public service.
‘Robin served the residents of the city because he believed that we could make a difference to the lives of the people we represent.
‘I’m deeply upset by the news having lost a colleague and friend.’