House Doctor: 'How can I stop gazunderers from cutting their offers at the last minute?'

Question: Can you help me ward off "gazunderers"? I put my two-bed flat on the market for £185,000 in September and have had plenty of offers as it's in a good Manchester neighbourhood. But I've twice had buyers drop out within a week of exchange and then massively drop their offer to a level that's just unacceptable – and I've pulled out. Is there anything I can do?

Mark Thorn, by email

Answer: It's popular, perfectly legal – and very painful. Gazundering is essentially a show of brinkmanship, the sharp practice of pulling out of a property purchase at the very last minute, unless the seller agrees to drop their price. It's a tactic increasingly deployed by aggressive buyers keen to exploit the fragility in the British housing market.

The price can often be forced down by as much as 5 per cent. Property prices ended a jumpy 2010 at roughly the same spot they started, the Nationwide says, with the average house hovering at £162,000. Yet although the building society's house price index recorded an unexpected 0.4 per cent rise in December, falls are anticipated early this year.

This means plenty of sellers will likely still be vulnerable to buyers happy to and force the issue, says Andy Montlake of the mortgage broker Coreco. "At the moment, up to a quarter of buyers try to renegotiate the price downwards at the last minute," he adds.

However, you can curb any further gazundering. One option, says James Brooks of Brooks estate agent, is to "have your solicitor draw up an agreement to go with a request for a non-refundable deposit to be taken on the acceptance of an offer".

Although it's a bold move, especially if you ask for a deposit of £5,000 or more, it will make it much less likely a buyer will reduce their offer.

"However, it will cost you solicitor's fees of around £400-£500, and many buyers may not agree to it," Brooks warns.

Alternatively, you could make it a condition that buyers must pay a smaller deposit – £1,000 say – into your solicitor's account and commit to complete the sale at the agreed amount.

And never forget the power of being pleasant – if you can strike up a decent rapport with a buyer, it can make it harder for them to knock your price down if they know you'll be hit hard.