UKIP leader Nigel Farage, arriving at the count for the Clacton by-election, told reporters that people were voting for change and it was not a protest vote.
Mr Farage said: "We have a career political class of college kids who've never had jobs in their lives and absolutely no connection with ordinary people. We need new people, we need change, real change."
He added: "This isn't a protest vote. When you analyse UKIP voters less than 10% are protest voters."
The Conservative MP for Witham in Essex Priti Patel, speaking from the Clacton by-election count, says a vote for UKIP will mean a Labour government at the next General Election.
Treasury Minister Priti Patel said: "We are seven months away from a General Election and the country will be deciding who they want as their Prime Minister. It's not UKIP, the choice will be between David Cameron and Ed Miliband. All a vote for UKIP will do is usher Ed Miliband into Number 10."
Ukip leader Nigel Farage has arrived at the Clacton byelection count.
Only just over half the 69,000 voters in Clacton voted in the by-election.
The voter turnout was 35,386 or 51.2% - which is less than the General Election turnout in 2010 of 64%.
The turnout in the Brightlingsea by-election for Essex County Council is 36.5%.
The vote was triggered by the resignation of the UKIP councillor Roger Lord, who was the party's candidate in the Clacton constituency until Douglas Carswell defected.
The votes have been verified at the same time as the Clacton constituency count.
The Liberal Democrat MP for Colchester, Sir Bob Russell, says a full moon is a "great omen" for UKIP as the party looks set to elect its first MP.
Douglas Carswell is favourite to retain his Clacton constituency after forcing a by-election when he defected from the Conservatives to UKIP.
Sir Bob said: "I arrived at Clacton Town Hall this evening and there's a full moon and a full moon is probably the best time for UKIP to win their first seat."
Nigel Farage believes UKIP is on the verge of securing its first elected MP as the votes are being counted in the Clacton by-election.Read the full story ›
One of UKIP's Euro MPs in the East of England says the mood among voters had changed and its not if UKIP will get seats but how many.
Tim Aker, who is also the party's Head of Policy, said: "It was only a few years ago they were saying, 'You'll never win anything, you'll never win anywhere,' and now the mood has changed, the debate has changed."
He added: "We can fight any party, any where. There aren't any safe seats for the other parties - we're coming to get them."
The Clacton by-election is set to re-shape British politics with UKIP predicted to gain their first elected Member of Parliament.Read the full story ›
All the ballot boxes from the 57 polling stations in the Clacton constituency had arrived at the count within an hour of the vote closing.
Counting is underway and a result is expected around 2 am.
Peter Kellner of the polling organisation YouGov has predicted a win for Douglas Carswell with an estimated majority of 10,000.
ITV News Anglia's Political Correspondent Emma Hutchinson reporting from the count at the Princes Theatre said: "The feeling here is that UKIP are confident that they have won it and believe they have won it well.