County and district councillor Doug Dew has announced he is joining the Liberal Democrats group from the Conservative party.
Cllr Dew represents Hemingford Grey & Houghton on Huntingdonshire District Council (HDC) and the Hemingfords and Fenstanton Division on Cambridgeshire County Council (CCC) and will join the Liberal Democrats on both county and district levels.
Cllr Dew said: "What particularly attracted me to the Liberal Democrats are their core values and their clear sense of ambition.
"I am really looking forward to continuing working with councillors and partners in improving the outcomes for local people."
Cllr Dew has represented the Hemingfords as a local HDC councillor for almost 24 years, and both leaders of HDC and CCC are looking forward to working closely with him in the Liberal Democrats.
Liberal Democrat Cllr Sarah Conboy, leader of HDC, said: "I have enjoyed working with Doug for many years.
"He brings a wealth of experience to the council and, in joining the Liberal Democrats, will be able to continue his hard work for the residents of all of Huntingdonshire."
Liberal Democrat Lucy Nethsingha, leader of CCC, said: "Doug brings with him an abundance of knowledge and expertise.
"I'm delighted he is joining us and look forward to working with him in our party as we face the many issues affecting Cambridgeshire."
Cllr Dew's decision further strengthens the 'Rainbow Coalition' at HDC and, with the Hemingford Grey and Houghton ward he represents worth two seats on the council, hinders the Conservative's position to try to regain an overall majority in the future.
Cllr Steve Count, group leader of the Conservatives at CCC, said: "I can understand why residents in the Hemingfords and Fenstanton area that voted for Conservative Doug Dew to win a seat would feel betrayed by his actions.
"If he felt strongly about joining the Liberal Democrats, he should have resigned his seat and stood for re-election as a Liberal Democrat.
"I am sure the short-term gain he receives from being a part of a coalition will be rectified at the next election when the electorate make their feelings known."
In a Twitter post, Cllr Jonathan Gray, group leader of the Conservatives at HDC, said: "I'm sad to see Doug leave the HDC Conservative Group.
"He was - and remains - one of my first friends in politics. I wish him well in the lush pastures of Liberal Democracy."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here