Ukip have moved a step closer to the Tories with a major pledge on the economy ahead of the general election.

Nigel Farage, ahead of his party's spring conference in Margate, said he would support the Chancellor George Osborne's plan to eliminate the UK's £90bn ($139bn) deficit by 2018.

But the Ukip leader warned he would only make the move if the Tories "stick to their promises".

"Let's face it, the Conservatives have failed totally on removing the deficit," Farage told the BBC. "People need to wake up to this. Our deficit, our national debt, has doubled in the course of the last five years.

"What Osborne will do is put before the next parliament another ambitious programme for deficit reduction. What we are saying is, if we are in a position of influence, we will do our very best to make sure this time it actually happens."

The Tories have downplayed the possibility of a Ukip-Conservative pact after May but Farage has previously said he would do "deal with the devil" to get Ukip into power.

Patrick O'Flynn, the party's economic spokesman and a former Daily Express journalist, is expected to outline some of Ukip's financial policies later on 27 February.

The commitment comes after a poll by Survation found that Farage is on to win the seat he is contending at the general election.

The survey, which questioned more than 1,000 voters in South Thanet, gave the Ukip leader a 11% lead over Labour (38.6% vs 27.6%) and put the Tories on 26.6%. The research also revealed Al Murray's The Pub Landlord has 1.4% of the vote.

The poll will boost the Ukip leader as he faces a tough fight in the Kent constituency in less than 70 days' time.