ALMOST half of Britons doubt whether the Conservative Government will meet its controversial immigration target even after the UK has left the European Union, according to a survey for the British Future think-tank.

The first official immigration figures since the Brexit vote will be published this morning.

David Cameron, the former Prime Minister, set the target of getting net migration to below 100,000 a year “no ifs no buts”. However, the current figure is more than 300,000.

Sunder Katwala, director of the think-tank, said: "Public trust in governments' competence to manage immigration - including meeting its own targets - is at rock bottom."

Read more: Poll - Brexit 'has not boosted the cause of Scottish independence'

Meantime, the Institute for Public Policy Research claimed in a separate report that the NHS "would collapse" without workers from the European Union, and called for them to be offered automatic citizenship as part of efforts to head off a "brain drain".

Britain is expected to seek to introduce controls on free movement rules following the referendum outcome but details of the system have yet to be outlined.

A poll of more than 2,000 adults for British Future examined attitudes regarding the aim to reduce net migration to five figures.

It found some 44 per cent thought it unlikely the UK Government would meet its target in the next five years as opposed to 37 per cent, who said it was likely.

Read more: Poll - Brexit 'has not boosted the cause of Scottish independence'

The report also said:

*12 per cent of people would like to see a reduction in the numbers of highly skilled workers migrating to Britain while 46 per cent would like to see more arriving;

*people were "less positive" about low-skilled workers moving to the UK with 38 per cent happy for numbers to stay the same or increase but 62 per cent said they preferred a reduction.

"The Brexit shake-up could be an opportunity to get immigration policy right - to restore trust in a system that works, and public consent for the immigration that we have," said Mr Katwala.

The IPPR paper cited figures suggesting there were currently around 55,000 EU nationals working in the English NHS and that one in 10 of the UK's registered doctors was an EU national.

"Without them, the NHS would collapse," the report said, recommending that the Government "makes a particularly generous citizenship" offer to NHS workers.

Read more: Poll - Brexit 'has not boosted the cause of Scottish independence'

It said all EU nationals who work for, or as locums in, the NHS should be eligible to apply for British citizenship.

The study called for a waiver of fees, English language and "life in the UK" tests, and residency requirements for all staff employed in public healthcare.

IPPR research fellow Chris Murray said: "Britain can ill afford to lose the talents of many EU migrants who have made Britain their home.

"EU migrants who are already here should get indefinite leave to remain. In particular, EU NHS workers should get the automatic right to citizenship. If they left, it would be a crisis for the NHS."

The status of more than three million EU migrants already in Britain came under scrutiny after the Brexit vote.

The Government has said it "fully expects" that the legal status of EU migrants living in this country will be "properly protected" when the UK leaves.