Ukip candidate Janice Atkinson says she is going to win Folkestone and Hythe from the Conservatives at the general election – and claims the evidence to prove it.

In a surprisingly bold prediction, Mrs Atkinson told Ukip’s spring conference in Margate that she would see off Conservative Damian Collins, who holds a majority of just over 10,000.

It followed a declaration by party leader Nigel Farage that Ukip could be on course to win “four or five seats” in Kent.

In a departure from her prepared text on the role of women in politics and business, she said:

“I am going to win in Folkestone and Hythe – my own private polling shows that.”

Her certainty of the outcome on May 7 took some observers by surprise and followed a warning by one of the party’s senior figures to candidates not to use hyperbolic language.

MEP Patrick O’Flynn, the party’s economic spokesman, said candidates needed to be wary of what they said during the campaign. He told the conference that leading Ukip figures must be “civilised in debate” and not resort to “hyperbolic” language.

“The next 10 weeks will involve all of us ... being responsible,” he said.

Prospective Liberal Democrat candidate Lynne Beaumont said: “She may think that but I do not think anyone should take the electorate for granted. People do not like it when you say you are going to win. It is not treating voters with respect.”

Green party candidate Martin Whybrow said: “Being so definitive could be seen as being over-confident and making assumptions that are not borne out.”

Folkestone and Hythe is being targeted by Ukip but Ms Atkinson's campaign has already hit a snag after one of the party's county councillors said he would not back her following a number of high profile blunders.

However, the party is focusing primarily on South Thanet, where Nigel Farage is hoping to be elected, and Rochester and Strood, where Mark Reckless is defending the seat he won at last year’s by-election.