Nigel Farage has denied accusations of a U-turn after Ukip dumped its immigration target just days after David Cameron faced humiliation for failing to meet his.

The eurosceptic leader unceremoniously dumped his party's pledge to keep the number of migrants below 50,000 a year, declaring the public were "bored" with "arbitrary" figures.

But Mr Farage insisted that Ukip remained committed to returning immigration to "normal" levels.

The move came as experts tipped the party to win six seats in May's General Election, enough to make them potentially significant players in any post-election negotiations.

The policy shift follows an attempt to rebrand the party as a serious, grown-up political force as its conference in Margate last weekend.

Ukip is campaigning heavily to ensure Mr Farage and a handful of other Ukip candidates are successful in May.

The party also hopes to come second in dozens of seats in the north of England, where it believes it can take large numbers of constituencies from Labour at the next general election in 2020.

Mr Farage said that Ukip would still aim to keep net immigration to between 20,000 and 50,000 a year.

The party would also ban all unskilled workers entering the UK for five years along with anyone suffering from a life-threatening illness.

Last year Mr Farage caused outrage when he suggested that those with HIV should be banned from coming into the country.

Ukip advocate an Australian-style points-based system for migrants.

Under such a scheme just 27,000 people would have been granted entry to Britain last year

Last week Mr Cameron under fire after figures showed net migration running at almost three times his stated target of 100,000 a year.

Mr Farage's declaration came just days after his party's immigration spokesman Steve Woolfe recommitted the party to the 50,000 figure.

Mr Woolfe also appeared to contradict Mr Farage yesterday, saying those with life-threatening conditions would be allowed in to the UK, as long as they had health insurance.

Mr Farage said that his party wanted to see migration numbers plummet to the same levels they were before 2000.

He said: "Normality was what we had from Windrush (1948) right up until the year 2000, where we had net migration into Britain ... between 20,000 and 50,000 people a year," he said.

Since then he said that the UK had "gone mad" and "as a result of our EU membership we have absolutely zero control over the numbers who come".

But he added that his party would not pledge to introduce "caps or targets ... you need to have more flexibility than that".

The Ukip leader also argued that the issue of migration was not just an economic one.

He blamed immigration for the crisis in Accident and Emergency wards in England this winter.

And he argued that immigration was hurting "the structure of our societies and communities and their feeling of togetherness."

Earlier experts said that Ukip could take as many as six seats in May.

Matthew Goodwin, professor at the University of Nottingham and the author of the book "Revolt on the Right" on the rise of Ukip, also forecast that Mr Farage would become an MP following a concerted campaign by the party.

And he predicted that UKIP could finish in second place behind Labour in as many as 60 seats in the north.