So far, Northumberland is the only council to have declared all of its results, with Reform making gains at the expense of both Labour and the Tories.
The Conservatives did enough to remain the largest party, winning 26 of its 69 seats, but failed to secure a majority, meaning the council is classed as being in no overall control.
Reform won 23 seats, with Labour on eight, independents on seven, Lib Dems on three and Greens on two.
Counting gets underway this morning for the rest of the local authorities where residents went to the polls on Thursday. Results are due to later this afternoon.
Reform is on track to take control of Lincolnshire County Council and Staffordshire County Council.
Mr Farage said: “We’ve dug very deep into the Labour vote and, in other parts of England, we’ve dug deep into the Conservative vote and we are now, after tonight there’s no question, in most of the country, we are now the main opposition party to this Government.”
Labour Party chairwoman Ellie Reeves said the elections “were always going to be a challenge” for her party, saying voters “aren’t yet fully feeling the benefit” of changes brought in since Sir Keir Starmer took office.
She added the elections were being held "largely in areas dominated by the Conservatives, often for decades".
The Conservatives, who are braced for a disastrous set of results, insisted they are trying to forge a new path under Kemi Badenoch, but said Sir Keir Starmer could be under huge pressure if Labour does not make significant gains.
The Liberal Democrats believe they have made "big gains" in the Conservative heartlands of 'Middle England'.
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