Cameron accused over £140,000 land payment

David Cameron was criticised yesterday for not disclosing that he had spent £137,500 on buying a plot of land next to his Oxfordshire home from a public relations boss.

The Prime Minister bought the land – including a short drive, a garage and a field – from Lord Chadlington, a neighbour, friend and chairman of his local Conservative constituency association. He is chief executive of Huntsworth, one of Britain's biggest PR groups.

Sir Alistair Graham, former chairman of the Committee on Standards in Public Life, said Mr Cameron should have registered the deal in the MPs' register of interests. "If you're doing a private deal affecting your personal interests with one of the heads of the largest lobbying firms in this country, then of course you should register that as quickly as possible," he said.

Aides said Mr Cameron used money left by his late father, who died last year, to clear up an anomaly under which he did not own his own drive or a field next to his garden which he maintained. The land involved would have been worth about £75,000 on its own but an independent valuation, taking account of the value it added to Mr Cameron's house, took the price to £137,500.

Downing Street insisted no conflict of interest could arise because money was being paid by the Prime Minister, not to him. A spokeswoman said: "He has never had a conversation about lobbying with Lord Chadlington or discussed his clients."