Britain's anti-EU UKIP party has made strong gains in local elections, taking seats from both Prime Minister David Cameron's Conservatives and the opposition Labour party, according to early results on Friday.
The gains by the UK Independence Party, which wants Britain to leave the EU, will pile pressure on Cameron to stiffen his approach to Europe and alarm some in his party who worry UKIP could scupper its hopes of winning a 2015 national vote.
In a sign the party could also do well in elections to the European Parliament, held on the same day, UKIP won 86 new seats in local elections in England, according to partial results from around a third of councils.
Labour won 94 new seats, the Conservatives lost 101 and the Liberal Democrats lost 84, according to early results.
UKIP leader Nigel Farage has siphoned support from all three main parties by tapping into discontent about the ability of politicians to effect change, particularly on immigration, which many Britons perceive to be overly high.
"I think Nigel Farage for quite a lot of those people is just a big sort of two fingers stuck up at what they feel is a sort of hectoring, out-of-touch elite," Jeremy Browne, a Liberal Democrat lawmaker, said on BBC TV.
The European elections, the results of which will only be announced on Sunday evening, in line with the rest of the EU, will determine the political persuasion of Britain's 73 lawmakers in the 751-seat European Parliament.
Cameron once called UKIP a party of "fruitcakes, loonies and closet racists". But Farage has denied his party is racist and promised to use the European and local elections to trigger a "political earthquake" in Britain.
His party made strong gains in traditional Conservative heartlands in places such as Essex in the south east of England and in Labour strongholds such as Rotherham in the north and Birmingham in the Midlands.
Cameron has promised to try to reshape Britain's ties with the EU if re-elected next year and to give Britons an in/out EU membership referendum by the end of 2017. UKIP wants an immediate referendum.
Local elections decide the fate of 4,216 local council seats.