UK Election 2015

UKIP: Could party squabble affect Brexit?

Nigel Farage
Chris Ratcliffe | Bloomberg | Getty Images

Just a week after the U.K. Independence Party (UKIP) scored its best-ever general election result, winning close to 4 million votes last Thursday, its leadership appears to be in disarray.

Nigel Farage, easily UKIP's best-known face, who briefly stepped down as leader after failing to win a seat in the U.K. parliament, is under attack from within the anti-immigration, anti-European Union (EU) party.

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Patrick O'Flynn, a UKIP Member of the European Parliament, told the U.K.'s The Times newspaper on Wednesday that Farage was "snarling, thin-skinned and aggressive" – and he wasn't the only person to criticise the leader.

The party's only member of the U.K. parliament, Douglas Carswell, who is viewed as a potential leadership candidate in the event of Farage's departure, has been involved in a tussle with Farage's staff over whether to spend all the money allocated to UKIP for parliamentary activities.

Can't renegotiate with EU on key issues: UKIP's Farage
Can't renegotiate with EU on key issues: UKIP's Farage

UKIP started a substantial damage limitation operation following O'Flynn's comments, with several key party donors and senior figures backing Farage. Farage himself dismissed the infighting as just "people letting off steam" after the election, in an interview with the BBC.

The party is expected to be a core part of the campaign to quit the EU in the referendum on the U.K.'s membership of the 28-country union, promised by the end of 2017. There are also likely to be some anti-EU Tory politicians campaigning to leave the EU, although the majority are expected to back Prime Minister David Cameron's stance of staying within the EU but renegotiating some terms of the U.K.'s relationship to the single market.

UKIP itself seems to be split between concentrating on the referendum, or on developing more domestically-focused policies.

(L-R) Labour le
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Following O'Flynn's comments about Farage, Paul Sykes, a UKIP donor, said in a statement: "As far as I'm concerned Nigel is the most experienced in the political field to be a powerful voice in the national referendum to hopefully achieve self government and control our own borders once again for this great nation of ours."

Some dismissed the backlash against Farage as just the standard fallout after an election result that did not quite meet expectations – the U.K.'s "first past the post" electoral system meant that while UKIP came second in 120 constituency seats, it only captured one.

Richard Desmond, owner of the U.K.'s Express Newspapers, said in a statement: "Nigel has my support 101 percent".

- By CNBC's Catherine Boyle