The number of "ridiculous" visa rejections are increasing, an MP has warned.

The statement comes as the Government prepares to reveal its future immigration plans.

SNP MP Patrick Grady said the Conservatives were running a "humiliating system" with unreasonable rejections being frequently overturned after appeals by politicians and journalists.

Speaking ahead of the long-awaited Government immigration plans, now expected to be published next week, Mr Grady said: "This is happening all the time.

"On a weekly basis we hear MPs trying to shoehorn questions about visa cases into debates.

"If you have a media or MP connection it does seem to have the effect of opening the door and getting the situation resolved, but that is not really fair or the right way to run a department."

The latest Home Office statistics show nearly 340,000 visa applications were rejected last year, a rate of 12.5%, but data on rejections being overturned is understood not to be available.

In one recent example, an assistant professor of English hoping to bring a group of schoolchildren on a language exchange trip had her visa denied, meaning the visit could not go ahead and families would be left thousands of pounds out of pocket.

SOL language school founder Grenville Yeo had arranged for the Ukrainian group to visit his charity in Barnstaple, as he has done for thousands of students over the last 30 years.

Maryna Shevchenko was the first group leader ever to have been refused a visa, when the Home Office decided she had not demonstrated she had sufficient funds to be able to return home, despite being a salaried university employee.

Mr Yeo said he was angered by the decision and believed the rejection was down to the hostile environment policy and all Eastern European visas now going through one British embassy in Warsaw, where staff are clearly overloaded and making mistakes.

He said: "Hearing the lead teacher, and therefore the whole group, was refused made me very angry because the reasons given were complete lies.

"The system now is heartless, but what is worse is that it is unprofessional and beyond that it does a lot of harm to the UK's reputation - although I know a lot of MPs would not care about that."