BRITAIN could dramatically reduce its net immigration from the current 300,000 to just 30,000 within three years if it left the European Union and took back full control of its borders, Nigel Farage has insisted.

The Ukip leader, launching his party's latest campaign poster on immigration in a pub car park and against the backdrop of the famous White Cliffs of Dover, also dismissed the pro-EU SNP as not a national party but a "European regionalist party" and predicted it would not form a left-wing alliance with Labour after the General Election because, together, they would not attain the necessary 326 majority number at Westminster.

Amid a media scrum in the Dover seat, which, with its neighbouring Kent constituency of South Thanet, Ukip is targeting, Mr Farage - kitted out in Home Counties wax jacket and corduroy trousers - unveiled the poster on immigration, which he described as the "number one issue" for many Britons.

The poster featured the White Cliffs with three escalators and the slogan "Immigration is three times higher than the Tories promised".

With waves crashing against the rocks just feet away and the coast of France visible in the distance, the party leader said he wanted to return migration levels to "normality" ie to those that existed between 1950 and 2000.

Mr Farage claimed the Tories did not have an immigration policy and to argue otherwise was a "wilful deceit".

Asked what normal levels of migration were, he said 30,000; recently the number given was 50,000. David Cameron famously declared how in the last parliament he would get net migration to below 100,000; it is now nearly 300,000.

"It will take a couple of years to get to that (30,000)," explained the Ukip leader. "If we had a referendum at the end of this year, within two years we would have all the details, so there is absolutely no reason why midway through this parliament we could not return to normality."

He claimed with current levels of migration Britain was not at ease with itself and an Australian points system, whereby the UK Government would control the numbers and types of people coming in, would be more at ease.

Mr Farage, asked about the types of people Ukip would not like to see entering Britain, referred to migrants with Aids, who were entitled to treatment that cost £25,000 a year. "The vast majority of people don't want that expenditure."

Noting how being in the EU meant the country had no control over immigration, he said: "We don't have control of our borders. If I could get the other party leaders to admit to that on Thursday night, I'll be pleased. If they want to make the argument immigration is a great benefit to this country, then let them make it."

The Ukip chief said he was "not particularly thrilled" by the prospect of a Lab-SNP alliance but said he did not think it would ever materialise.

"Everyone is getting very excited about the number of seats the SNP are going to win; not surprisingly. But in taking seats from Labour, they are not adding to the centre-left equation. It's still looking pretty unlikely that Labour and the SNP together would get the 326 number."

He said there was "a lot of nonsense" talked about the way Scottish views differed from English ones but noted: "When you look at polling on immigration and the Europe question what's really interesting is how similar the views in Scotland are to those in England; quite surprisingly so."

Asked if UKIP's plan to review the Barnett Formula and shift £8bn from Scotland to England was a vote winner north of the border for Ukip, Mr Farage replied: "Honesty is sometimes a vote winner," adding: "We want the Union to operate on a fair basis and at the moment the English have had a pretty rotten deal out of it."