Gazundering is sweeping back into the London market, with buyers of expensive properties slashing their prices in the last week – after offers have already been agreed.

It follows last week’s Autumn Statement on Stamp Duty Land Tax – which has resulted in cuts in the tax for the majority of buyers, but hikes for those purchasing property over £937,500.

Buying agent Henry Pryor said: “Yes, gazundering is back.

“I have revised my offers on behalf of clients on two properties as a result of the Autumn Statement, one by £125,000 and one by £87,000.”

Pryor said that the buyers dropped their offers within 24 hours of George Osborne sitting down after delivering news of the Stamp Duty reforms.

He said both of the reduced offers were accepted, and that the one with the reduction of £87,000 has now exchanged.

Pryor told Eye: “We were desperately English about it – very politely telling the vendors to blame the Chancellor and not us.”

In other cases, buyers have reportedly slashed their offers at the last minute by up to £500,000 – or are putting in much lower offers in the first place.

Ed Mead, of Douglas & Gordon, said one purchaser had offered £2m on a house marketed at £2.5m and said: “That’s not uncommon.”

While the changes in SDLT, which kicked in at midnight last Wednesday, have benefited most buyers, the cost for purchasers of expensive homes has soared.

For a £1m property, SDLT has gone up by £3,750 from £40,000 to £43,750.

For a £2m house, the tax has shot up by £53,750 from £100,000 for £153,750.

And for a £5m home, it has gone up by £163,750 from £350,000 to £513,750.