Nigel Farage's Reform UK party has taken six councils from the Conservatives and control of Durham so far in the local elections.
Durham CC, while it has been in no overall control since 2021, was run by Labour from 1925 to 2021.
A spokesperson for the LGiU think-tank said: ‘Reform has not just pulled it off [winning Durham], but has surpassed our and many other people's expectations, by securing 55 seats – and counting – with 98 in total being contested.'
The other councils Reform now has control of are Derbyshire, Kent, Lancashire, Lincolnshire, Nottinghamshire and Staffordshire, all won from the Conservatives.
Kent has traditionally been a flagship council for the Conservatives. Although there is no overall control in Leicestershire, Warwickshire, Worcestershire and Northumberland, Reform has also made gains in these areas.
The Tories have also lost control of Devon to no overall control.
In Cambridgeshire and Peterborough the Conservatives have chalked up a win, with Paul Bristow winning the mayoral post formerly held by Labour.
Former Olympic boxer Luke Campbell won the mayoralty for Reform in Hull and East Yorkshire.
In Greater Lincolnshire, Reform won its first mayoral contest this morning, with Andrea Jenkyns getting 42% of the vote.
So far the Lib Dems are up by 117 councillors to 287 and are hoping to do well in Gloucestershire and Hertfordshire. The Greens have 33 more councillors so far, with a total of 61.