British National Party supporters claim it is "on its way" after doubling its number of councillors in England.
The BNP has become the second party in Barking and Dagenham
The biggest gains were in Barking and Dagenham, where it seized 11 of the 13 seats it contested, becoming the second party. One ward has still to declare.
The BNP also won seats in Epping Forest, Stoke-on-Trent and Sandwell.
The party fielded more than 350 candidates and now has 46 seats in England. Before Thursday's local elections it held about 20 of 22,000.
Barking Labour MP Margaret Hodge has been criticised for saying during the campaign that 80% of white families in the area were "tempted" by the BNP.
Barking and Dagenham is the first council in the country to have the BNP as the second-biggest party.
It also picked up three seats in Stoke-on-Trent, where Labour lost overall control, and three more in Sandwell in the Black Country.
It took a further three in Epping Forest, in east London.
The BNP won single seats in Solihull, Redditch, Redbridge, Pendle, Leeds and Burnley. However, it lost a seat in Bradford.
BNP leader Nick Griffin said the party had benefited from "people wanting to kick the Labour Party really hard and we're the politically incorrect way to do it".
He added: "When you look at some our results elsewhere in the country where we've hammered the Conservatives as well, this is a revolt against the entire liberal political elite by the hardworking people of Britain who resent being taxed to have our country transformed."
Russell Green, who won a seat in Sandwell, said the BNP was "on its way".
He added: "It is plain to see that the vast majority of us are sick and tired of the dishonest and self-interested politicians that are ruining our communities and our country."
When asked about the BNP, Environment Secretary Margaret Beckett told BBC Radio 5 Live: "They are deceitful. They are very unpleasant, nasty people who try to exploit problems and try to turn people against each other. They are very dangerous."
But Mr Griffin said: "We're not a Nazi party. People can look at our manifesto online and see we're committed to a libertarian position in many things, and most certainly to the extension let alone the maintenance of democracy."
The BNP claimed a shock win from Labour in Solihull when it won the Chelmsley Wood ward by 19 votes, securing its first seat on the council.
Speaking after the vote, which saw the Conservatives retain control, winning BNP candidate George Morgan said it was a victory for the ordinary working man.
He said: "This is Labour's third term and they've done nothing for the country. People are sick and tired of all the lies. We are offering people a choice."
His Labour opponent, Nicholas Stephens, said: "It's a very disappointing result but the BNP were quite close two years ago so it's not surprising, what with the events going on nationally over the past two weeks.
"You don't have to be a genius to work out why some Labour voters either stayed at home or switched to other parties."
Mrs Hodge said: "We have to challenge the values of the neo-Nazi party."
On her comments during the election campaign, she added: "My aim was not to give the BNP publicity but to raise awareness of the issues. It is something I have been saying for some time.
"I think we must have a much more open policy on the issue of race. This is something that affects the whole of the political spectrum, not just the Labour Party.
"This is an issue that we have all failed to address properly, I feel."