Nigel Farage, leader of the UK Independence party, is on course to win his battle to become an MP, according to a poll in South Thanet showing him with an 11% lead.

The poll conducted by Survation over the past week shows Farage on 38.6%, Labour on 27.6%, the Conservatives on 26.6%, the Greens on 3.1% and the Liberal Democrats trailing behind with 2%. It is the first time Farage has drawn ahead in what previous polls have said is a tight three-way contest in the Kent constituency.

Al Murray, the comedian who is standing as the Pub Landlord candidate, has 1.4% of the vote.

Ukip said the poll was the reward for the hard work Farage and the party had devoted to the seat over the past six weeks.

The poll has a sample size of 1,011 with the fieldwork conducted between 18 and 20 February. The poll was funded by Alan Bown, a longstanding Ukip donor who has funded other polls in Ukip marginal seats.

Farage, who is preparing for his party’s spring conference, will be delighted that the Conservatives are not in second place, making it harder for them to credibly urge Labour voters to switch to the Tories to stop the Ukip leader entering parliament.

A previous Survation poll in the constituency in November found Labour ahead on 35%, with the Conservatives at 28% and Ukip 30%, suggesting Labour has slipped back due to Farage’s decision to stand.

The Ukip leader has been spending more time in the constituency after he faced criticisms from the Tory candidate Craig Mackinlay, a Medway councillor, about his lack of presence since he was selected in August. The Tories won the seat in 2010 with a majority of nearly 8,000 over Labour, securing 22,043 votes, nearly half of those cast.

The Ukip conference is being held in Margate, just inside the South Thanet boundary, as a symbol of the party’s commitment to the area.

Farage is in the US this week to attend the the hard-right Conservative Political Action conference (CPAC) in Washington, DC, alongside high-profile Republicans including Sarah Palin, Jeb Bush and Rick Santorum. He is thought to be the first British leader to speak at the event, where he has been given star billing between Palin’s speech and a reception held by the National Rifle Association gun lobby.

Before his speech, the Ukip leader gave an interview to Fox News, where he has built a following of viewers, warning that “the mosques of Britain” have been infiltrated by criminal preachers who should be arrested.

Asked about the recruiting of jihadis from the west, Farage said the UK had been “appeasing” Islamic extremists and warned that religious minorities need to understand the law of the land.

“We have allowed different communities to develop a different culture within what ought to be a Judeo-Christian culture,” he said. “In the case of my country, our constitution makes it perfectly clear. That is what we are as a country. And whilst we want to be tolerant of other religions and other minorities, they have got to understand the law of the land in our country. We have lost sight of that.”

The party stumbled on Thursday, however, when the chair of Ukip’s lesbian, gay, bisexual and transgender group resigned over concerns that the party’s leadership has failed to set “a gay-friendly tone”. Announcing his resignation on Twitter, Tom Booker said that his departure was because he “simply couldn’t defend the party any more”.

• This article was amended on Friday 27 February 2015. The Kent constituency for which Nigel Farage is standing is South Thanet, not Thanet South as we had it originally.