Peter Chalke edged out Paul Bettison by just 60 votes in the battle to become the Tory leader on the Local Government Association, following an often fiery contest that was decided on a recount.
Mr Bettison had described his opponent as unreconstructed during the campaign but, at a group meeting at the LGA Conference on Tuesday, the Bracknell Forest BC leader threw his weight behind Mr Chalke following the declaration of the result.
Mr Chalke, who was replaced as deputy leader by Margaret Eaton, said his leadership style would be more inclusive and team-focused than outgoing head Gordon Keymer.
He said: 'There will be some change. I need to stamp my authority on the leadership.'
But he told party members on Tuesday that he would not be giving LGA chairman Sir Jeremy Beecham an easy ride if cross-party co-operation meant reneging on Conservative principles.
At the general assembly, Sir Jeremy congratulated Mr Chalke on his victory and said: 'We've had many happy hours sparring in the LGA executive.'
LGA vice-chairman Sir Sandy Bruce-Lockhart, who did not vote in the leadership election to remain impartial, said of Mr Chalke: 'He's politically sensitive and I am sure that he will build a very strong team.'