Media playback is unsupported on your device Media caption The BBC's Robin Brant reports from inside UKIP's 'get Nigel elected' rally

UKIP will back the Conservatives' deficit reduction strategy in the next Parliament but only if they "stick to their promises", Nigel Farage has said.

Speaking ahead of the party's spring conference, Mr Farage said UKIP would back future Tory budgets if they helped eliminate the current deficit by 2018.

He said George Osborne had failed to meet his deficit targets since 2010 because he had shirked "tough choices".

UKIP would quit the EU, axe HS2 and cut the foreign aid budget to save cash.

In a speech to UKIP activists in Margate, Kent, Mr Farage said he was "optimistic", "upbeat" and "bullish" about his party's chances at the general election.

'Famous victory'

He predicted the party would get a "good number of UKIP MPs over the line" and emerge as the "main opposition to the Labour Party" in the north of England.

"I believe in Britain, I believe in you, I believe we will score a famous victory on 7 May," he said.

Mr Farage added that the campaign for the general election had begun in January and was the longest and most negative in history.

"People of this country need the politics of hope and of inspiration that says things could be better," he said.

It would not be easy for UKIP, he said, because the whole of the political establishment was against the party and he urged candidates who might face attacks to "ignore it, turn the other cheek and tell voters what we stand for".

The party, which had its first two MPs elected to Westminster last year, is seeking to boost its representation further, with an eye on potentially holding the balance of power in the event of another hung Parliament.

Image caption Mr Farage is hoping to be elected to Westminster in May

The Conservatives have dismissed talk of potential post-election deals with UKIP although Mr Farage, who is standing in the Thanet South constituency in Kent, has suggested he would "do a deal with the devil" if it would lead to an early referendum on the UK's future in the EU and the UK ultimately leaving the union.

'Position of influence'

Asked if he would support a future Conservative-led government if it was reliant on UKIP votes to get Budget proposals through Parliament, Mr Farage said he would, but only if it "sticks to its promises" to reduce the £90bn deficit on day-to-day spending.

"Let's face it, the Conservatives have failed totally on removing the deficit," he 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 George 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 government argues that it has halved the annual budget deficit since 2010 but Mr Farage said the Conservatives' attempts to go further had been hampered by their Liberal Democrat coalition partners.

"George Osborne was right to say he would eliminate the deficit by the start of 2015 but he failed to do it because he had coalition partners who did not appear to be very interested and he did not himself make some of the tough choices."

'Fight on'

UKIP says leaving the EU would save about £8bn a year and that it would also cut £9bn from the annual foreign aid budget by focusing only on the most urgent projects. It also says abandoning the HS2 high-speed rail link could save up to £50bn.

"We have some positive ideas and these are the kind of things we will be arguing for," Mr Farage added.

In his speech to the two-day conference, UKIP deputy leader Paul Nuttall said there was a "fight on" for the future of the UK in the aftermath of the Scottish independence referendum.

He attacked the SNP for saying they would vote on Commons legislation directly affecting England.

Immigration spokesman Stephen Woolfe said policymakers had "taken their eye off the ball" for a decade about the impact of migration on infrastructure.

"Schools are now full, hospitals are troubled, healthcare - it is very difficult to be seen in many areas of this country," he said.

The Conservatives have said they are also aiming to achieve an absolute surplus - covering both day-to-day spending and capital investment - by 2019, while Labour say they will get day-to-spending into into surplus by 2020 at the latest.