David Cameron has refused a request to release statistics that Eurosceptics say will prove how many EU migrants actually enter Britain every year.

HMRC issues thousands more national insurance numbers to EU migrants than officially arrive in Britain but the tax office has repeatedly refused to publish the figures on the grounds that it might influence the outcome of June's EU referendum.

Leading Eurosceptic Tory MP David Davis demanded the Prime Minister step in to tell HMRC to release the figures 'immediately' so voters are given the 'truth' about EU immigration.

Figures published by the Office of National Statistics (ONS) last month found 257,000 EU migrants came to the UK last year but over the same period 630,000 EU citizens registered for a national insurance number

Leading Eurosceptic Tory MP David Davis (pictured left at Prime Minister's Questions today) demanded the Prime Minister (pictured right) step in to tell HMRC to release the figures 'immediately' so voters are given the 'truth' about EU immigration

A national insurance number is needed to get a job or claim benefits in the UK and whereas UK-born nationals are automatically assigned a number, those arriving from abroad must register with the Department for Work and Pensions, meaning the Government holds the data on record.

Figures published by the Office of National Statistics (ONS) last month found 257,000 EU migrants came to the UK last year but over the same period 630,000 EU citizens registered for a national insurance number.

In the last five years 2.25million EU nationals have registered for a national insurance number but according to the ONS just one million EU citizens have arrived in the country in the same period.

HMRC has refused to say how many of those national insurance numbers given to EU workers are active and have left the gap between the two sets of data unexplained.

ROMANIAN AND BULGARIAN IMMIGRATION UP BY 38 PER CENT The latest immigration figures from the Office for National Statistics found that in the 12 months to September 2015: 617,000 people arrived in the UK. This is up 0.3 per cent on the previous year. 257,000, or 42 per cent, arrived from the European Union. This figure is up 4 per cent on the year. 130,000, or 21 per cent, arrived from the 'EU15' group of countries: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, Netherlands, Portugal, Spain and Sweden. This figure is up 5 per cent on the previous year. 69,000, or 11 per cent, came from the 'EU8' group of countries: Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Slovakia and Slovenia. This figure fell on the year by 9 per cent. 55,000, or 9 per cent, came from Bulgaria and Romania. This was up 38 per cent on the year. The remaining 2,00 (0.3 per cent) came from Malta, Cyprus and Croatia. This figure was down by 60 per cent on the previous year. Advertisement

'For five or six years national insurance numbers issued to EU migrants have been hundreds of thousands higher than the official immigration figures,' he said at Prime Minister's Questions today.

'This implies the official immigration figures may be a dramatic underestimate.

'We can only know the truth of the matter if HMRC release their data on active EU national insurance numbers, which has HMRC has refused to do.'

But Mr Cameron dodged the question, insisting that the reason why the national insurance numbers and official migration figures do not match is because workers can get a national insurance for a 'very short-term visit'.

'People who are already here but without a national insurance number can apply for them. So these numbers are quite complex,' he added.

But former civil servant Jonathan Portes, who has had several requests for the figures rejected by HMRC, said the 'huge discrepancy' between the number given national insurance numbers and the number who officially enter the UK could not be explained by short-term visits.

'It is massive and it did not used to be this big,' he said, and accused the Government of trying to cover up the true extent of migration from the EU.

'The Government is hiding this data. They claim it would interfere with the renegotiation. It is genuinely outrageous.

Which ever side of the argument you are, on immigration or on the EU, the electorate deserves to have the facts and the data.'

Figures published by the Office of National Statistics last month found 257,000 EU migrants came to the UK last year but over the same period 630,000 EU citizens registered for a national insurance number.

Writing later on his website, Mr Davis said: 'It is an old cliché that there are three kinds of lies: lies, damned lies, and statistics.

'But this week the Government has breathed new life into this rule, as they showed that they are willing to bury the true scale of immigration into the UK with the help of some very dodgy statistics.'

THE QUEEN'S SPEECH IS DELAYED AS DAVID CAMERON THROWS EVERYTHING AT WINNING THE EU REFERENDUM The Queen, pictured with Prince Philip during last year's State Opening, does not yet have a date for her next visit to Parliament for the State Opening The Queen's Speech is set to be delayed until after the EU referendum as the Government throws everything at the historic poll. The set-piece constitutional occasion has generally been held in May following the move to fixed term Parliaments in 2010. It is an annual occasion for the Government to announce its legislative plans for the year ahead and sees a full display of Royal pageantry as the Queen visits Parliament to read out the remarks. But the ceremony has reportedly been pushed back to after the June 23 referendum as David Cameron plans for how he will bring his party back together. The Times said the event would be accompanied by the expected post-referendum reshuffle as the Prime Minister bids to get back on the front foot. When it comes, the speech is thought likely to include prison reforms, an expansion of health devolution and further legislation to end discrimination. Advertisement

'It's like Halloween come early': Latest document released by David Cameron warning of Brexit risks dismissed by his own ministers as a 'dogy dossier' and 'yet more scaremongering'

David Cameron's latest report on the warnings of leaving the EU has been dismissed by his own ministers as more 'scaremongering' and was even mocked as 'like Halloween come early'.

The fresh analysis from government officials claimed a Brexit would lead to rising food and clothes prices and fewer jobs.

But human rights minister Dominic Raab hit out the Government report on the alternatives of EU membership, saying it was just the latest 'scare story... about the ghoulish prospects outside the European Union'.

And Iain Duncan Smith, one of the leading Eurosceptic Cabinet ministers, branded the document a 'dodgy dossier'.

David Cameron (pictured left leaving Downing Street this morning) was accused of publishing more 'scaremongering' warnings by his own justice minister Dominic Raab (pictured right), who said the 'scare stories' circulated by the Government was 'like Halloween come early'

The paper - which looks at arrangements adopted by Norway, Switzerland and Canada as well as the option of falling back on World Trade Organisation (WTO) rules - will say each would carry serious risks if they were adopted by the UK.

Foreign Secretary Philip Hammond insisted the report showed the UK enjoys the 'best of both worlds' and warned negotiations to set up free trade agreements following a Brexit could take longer than the Second World War.

'Hard-headed analysis shows that every alternative to remaining in a reformed EU would leave Britain weaker, less safe and worse off. Working people would pay the price with few jobs and rising prices,' he told the Today programme.

The publication of the report indicates the Prime Minister is undeterred by accusations that he is running an unrelentingly negative campaign - dubbed 'Project Fear' by critics, including Boris Johnson - as he leads the fight to keep Britain in.

Iain Duncan Smith (pictured right) dismissed the latest document released by Philip Hammond (pictured left) as a 'dodgy dossier'

It follows hard on the heels of another Government paper earlier this week which warned the country would face a 'decade or more of uncertainty' if it chose to leave as it painstakingly negotiated new trade deals.

And it also warned that after the initial two-year transitional period after cutting ties with Brussels, UK citizens living or on holiday abroad could be left stranded.

BORIS STORMS AHEAD IN THE RACE FOR NUMBER 10 Assuming the two men make it into the run off, both pick up ground - but the poll suggests Mr Johnson still wins the race for No 10 by 56 per cent to 38 per cent Boris Johnson holds a more than 20 point lead over George Osborne in the race to be the next Prime Minister. Tory activists will choose the resident at No 10 for the first time ever when David Cameron stands aside. He has already made clear he will quit before the next election and his career could be brought to an abrupt end by defeat in the EU referendum on June 23. Party rules require Conservative MPs to whittle down the field to just two contenders before Tory members make the final choice. And today's YouGov poll for The Times shows Mr Johnson is the clear front runner. He stands far ahead on 43 per cent, leading Mr Osborne's score of 22 per cent. Assuming both men made the run off, a forced choice in the poll shows Mr Johnson sweeping to victory Mr Osborne by 56 per cent to 38 per cent. In the overall poll, Theresa May is a close third on 19 per cent, according to the survey of more than 1,000 party members. Newer choices, who only entered Parliament in 2010 and reached the front rank of government in the second half of the last Parliament, were far behind. Sajid Javid scored 7 per cent in the poll and Nicky Morgan, who has already declared she would like to run, scored just 1 per cent. Mr Johnson would beat Mrs May by 20 points if they contend the final run off. Mr Osborne appears set for a narrow win over Mrs May if they are chosen as the final candidates - the poll suggests he leads 46 per cent to 42 per cent. As Chancellor and a key ally of the Prime Minister, Mr Osborne has long been seen as the strongest contender to take over from Mr Cameron. But he had a dangerous run in with Conservative MPs - particularly newly elected MPs - over planned cuts to tax credits. A rebellion on his own benches forced him to an expensive u-turn as he threw out the whole £4.4billion cut at November's autumn statement. Advertisement

The latest paper examines the arrangements which other countries outside the EU have adopted - and finds none offers the advantages of continued membership.

Pointing to the example of Norway, the document says Oslo still has to make a significant contribution to EU spending and accept three-quarters of EU laws with no votes or vetoes.

It also has to accept the free movement of people, with EU migrants accounting for a higher proportion of the population - 6 per cent - than they do in the UK where it is 4 per cent.

But Mr Raab, mocking the latest government report, told the BBC: 'I think that there has been far too much scaremongering.

'It's like Halloween come early; we have a scare story each week about the ghoulish prospects outside the European Union.

'I don't believe in ghosts and I'm not afraid of these ghoulish stories of life outside the EU.'

Warning the Prime Minister of running a negative campaign, he added: 'I think there's been far too much scaremongering. I think there are brighter opportunities for Britain in terms of lower food bills, lower energy costs, freer trade from Latin America to Asia, which of course are the growth areas for the British economy and exports. That's where the real advantages lie.'

The Government report cites Switzerland and Canada as countries that have only limited access to the European single market, despite trade deals which have taken years to negotiate.

The paper says that if similar arrangements were adopted by Britain, the UK financial services sector would face increased costs as they would no longer have 'passports' allowing them to sell to the EU market.

Like Norway, Switzerland has to accept the free movement of people with almost four times as many EU nationals living in the country as a percentage of the population as there are in the UK.

The most drastic option, if the UK failed to reach a deal with the EU, would be to fall back on WTO rules, the paper states, which would mean new tariffs on UK exports hitting companies with supply chains in Europe.

Mr Hammond said: 'It is not credible to suggest that you could have continued access to the single market without having to accept freedom of movement of labour, without having to accept EU regulations, and without having to contribute to the EU budget.

'Now maybe the Leave campaign wants to say they are prepared to accept all of those things, but if you accept all of those things surely we are better off inside the European Union with our seat at the table, helping to shape those rules as well as being bound by them.'

Mr Cameron also challenged the Leave camp to set out 'what their detailed plan for Britain outside the EU is - and its impact on the economy and prices'.

But in a further deepening of Conservative divisions, Work and Pensions Secretary Mr Duncan Smith said the 'real uncertainty' lay with the EU 'project'.

'As each day passes we see yet another example - from the utter failure to cope with the migrant crisis, to the increasing disaster of the euro,' he said.

'This dodgy dossier won't fool anyone, and is proof that Remain are in denial about the risks of remaining in a crisis-ridden EU.