Image caption Students have drawn up a protest petition to highlight the delays to processing visas

Overseas students in the UK are complaining they are trapped in a legal limbo by visa delays which mean they do not have the right either to stay or go back home.

Students claim they have waited for up to five months without their passports.

Hundreds have signed a protest petition claiming their "basic rights" are being denied by delays in processing visas.

The UK Border Agency said applications from students would be "worked through by the end of the summer".

'Complete outrage'

The National Union of Students (NUS) says this is becoming a "serious problem" and a "complete outrage" which puts at risk the ability of UK universities to attract overseas students.

A US student, Jordan Junge, who has just finished a £17,000 masters degree at the London School of Economics, says she has been waiting for almost five months for her visa to be processed and her documents returned.

Students should come to the UK to study, not work. That is why this April we stopped the automatic right for students to stay on and find work after their studies UK Border Agency

The student from Colorado says that this became "extremely stressful" when her grandmother was taken seriously ill and her parents told her to come home.

"Even if you order a pizza from Domino's you can track its progress - but I've no idea about what's happening to my passport."

She says that there are other students who have children that they cannot get back home to see.

Ms Junge says she wanted to carry out further study at the LSE which would have involved travelling outside the UK this summer, but the uncertainty over her documents is making this "very unlikely".

And she says that the tightening of the student visa system is putting off many other US students.

Along with other students, she was particularly concerned about the inability to communicate with UKBA, and so far the information she has obtained has come via her MP.

'Deplorable service'

A Canadian PhD student in Edinburgh, who submitted documents at the beginning of April, says the delays have been "incredibly stressful and distressing" - and she is still uncertain whether she will be able to catch her flight home in a few weeks.

An online petition, signed by more than 600 people, says "the deplorable quality of service provided by the UKBA ill befits a nation like the United Kingdom".

The overseas students who have been caught in this delay are those who have finished their courses and have put in applications to remain longer in the UK.

Vulnerable students are now stuck in the UK unable to work, unable to go home to their families and unable to get on with their lives National Union of Students

These post-study visa applications cost more than £500 to process and require students to get their fingerprints taken and to submit their passports.

The visa rules changed in April - and it has been suggested that this prompted an increase in applications ahead of the deadline which has left individuals caught in a bureaucratic backlog.

A South American student, who has just finished a PhD, told the BBC that it had put students in an impossible position.

He said students could not apply for jobs in the UK because they had no proof of their right to be in the country - and they could not go abroad or return home for work because they had no passports to travel.

A UKBA spokesperson said: "Students should come to the UK to study not work. That is why this April we stopped the automatic right for students to stay on and find work after their studies.

"The remaining applications will be worked through by the end of the summer and applicants will be contacted once a decision is made.

"Anyone who wishes to withdraw their application and have their documents returned can do so by contacting the immigration inquiry bureau."

But Daniel Stevens, international students' officer for the NUS, said: "It is clear that delays to the processing of visa applications is becoming a serious problem.

"International students are facing the direct financial and emotional costs of an under-resourced UKBA.

"Having paid thousands of pounds in visa application fees and after facing a raft of bureaucratic procedures, their applications have now been put in put in a pile with little hope of being processed in a timely manner.

"As a result, vulnerable students are now stuck in the UK unable to work, unable to go home to their families and unable to get on with their lives."

James Pitman, UK managing director at the Study Group international education firm, said: "We need to make the UK as appealing an education destination as possible - hold-ups like these do not help."

Earlier this year, a group of UK universities called on the government to remove overseas students from immigration figures.

But the government rejected such suggestions, saying that targets to cut immigration could be achieved without "fiddling the figures".