Sir Alan Sugar is grounding “high risk” customers from using his private jet company, Amsair, in a bid to stop loosing money.

The business which took off in 2004 used to allow credit for customers wanting to charter its planes, however, these customers will now have to pay up front or find themselves being turned away.

Experts confirmed that the difficult economic climate was hitting corporate jet firms hard with many multi-national businesses choosing to use commercial airlines instead.

The Royal Bank of Scotland has recently cancelled an order for a £35m jet, ordered by Sir Fred Goodwin, before he resigned.

A spokesperson for Amsair confirmed that changes had been made to some parts of the business and they were concentrating on private clients who hire their 13 seat executive jet, while trying to cut out third party charters and high risk business.

Bookings for private jet charter have dropped by 20% across the UK in the last year as companies tighten their financial belts.