Their value has fallen fast and furious, down from a peak of 487 pence shortly after the stockmarket flotation two and a half weeks ago to 240p by close of trade on Friday - a drop of more than 50%.

Lastminute.com delivers ... but not to shareholders yet

As the share offer price was 380p, investors have suffered a loss of 40%.

Many have been unable to cut their losses and sell the shares because certificates have been slow to arrive.

At least one investor contacted the BBC as late as Friday morning to complain that he had still not received his certificate.

Cheques 'countermanded'

Other investors have experienced problems with getting a refund from the company. The money is due to them as their share allocation was smaller than the amount of stock they had applied for.

Some cheques have been slow to arrive, although Lastminute.com has promised that people will get their money back plus 4% per annum in added interest.

However, some investors, whose cheques have arrived, got a nasty surprise when they tried to cash them.

Payment was refused and the cheque came back stamped "Payment countermanded by order of the drawer".

Lastminute.com told the BBC's Working Lunch programme that "there might be a few more cases like this but we would be horrifed if there were many more.

"We are very suprised at this event and can only say we will do everything we can to rectify the situation as soon as possible. There has been absolutely no block cancellation of cheques."