Card trick trumps Charles 

Despite being one of the country's wealthiest landowners, Prince Charles pulled in his purse strings in response to the economic crisis, and revealed how he had managed to slash £500,000 from his personal spending bill.

He installed energy monitors in his office, gave up expensive skiing trips to Switzerland in favour of holidaying in Scotland, and encouraged his wife to recycle her coutured dresses.

All this, however, has not impressed thousands of tenants on his Duchy of Cornwall estate - which last year earned him a mere £16.4million - who are struggling to pay rent increases imposed by Charles's land stewards of around 11 per cent.

Now one tenant, Fiona Dobson, 51, who rents a three-bedroom home on the Isles of Scilly is, I can reveal, hoping to meet the increase by selling Christmas cards sent to her by Charles on internet auction site eBay.

The mother of two, who takes home £200-a-week as a shop manageress, put two signed cards up for sale for a starting sum of £100 each - one from 1993 showing Charles with Princes William and Harry, and the second a 1988 card of the Prince with Princess Diana.

Says Fiona, whose farm labourer husband also works for the Duchy: 'The Duchy owns nearly all the land on the islands and they used to put rents up in line with inflation. But in recent years, the rents have shot up on average 11 per cent every year, way above the rate of inflation.

'Our rent is £520-a-month, a quarter of the money my husband and I take home. And we're among the lucky ones, as we're protected tenants. 'It's no good writing letters to the Duchy - you get nowhere. In fact, one Duchy steward some years ago told me that if I didn't like it, I should go and live in a council house. I'll write again, but I don't hold out much hope.'

In her eBay posting, Fiona writes: 'Reason for selling to help pay Duchy rent.'