London, Oct 10 (IANS): The Eurosceptic UK Independence Party (UKIP) secured its first ever seat in Britain's House of Commons Friday after the party secured a landslide victory in an east England by-election.

Douglas Carswell, a former Conservative Party member of parliament (MP), defected to the UKIP in August, triggering a by-election in his constituency of Clacton, a town in Essex.

The incumbent MP won a decisive victory in Thursday's by-election securing 21,113 of the 35,386 votes which enabled the UKIP to enter British Parliament for the first time, Xinhua reported.

"We must be a party for all Britain and all Britons, first and second generation as much as every other. Our strength must lie in our breadth. If we stay true to that there is nothing we cannot achieve," Carswell said Friday in his victory speech.

"British political history was made in a seaside town in Essex early this morning when Douglas Carswell was returned as UKIP's first elected MP," UKIP announced on its Twitter feed.

UKIP leader Nigel Farage described the win as "the biggest and best night in UKIP's history".

"What it shows is that the UKIP is now a truly national party; indeed, we are the only party that can challenge in solid Tory and Labour areas," Farage said on Britain's Sky News.

In another by-election held Thursday, the UKIP also garnered substantial gains by increasing the party's share of the vote from 2.6 percent to 38.7 percent in Heywood and Middleton, a constituency in Greater Manchester in northern England.

The Labour Party retained the seat in the constituency but the UKIP sharply slashed its majority.

Farage said the rise in UKIP votes in the region, a traditional Labour Party stronghold, was "a brilliant performance.".

In May, the UKIP won the European Parliament elections in Britain, marking the first time for the right-wing party, founded in 1993, beat all traditional mainstream parties in the country.