David Cameron's constituency president has said he believes lobbying needs to be regulated.

Speaking on the BBC Radio 4 Today programme, Lord Chadlington said there was a clear difference between PR and lobbying.

Mr Cameron faced controversy last month after it emerged he had paid £137,000 for a piece of land he bought at his constituency home from Lord Chadlington.

But the peer, who runs PR firm Huntsworth, told Today: "Lobbying is not about public relations, that's about the relationship between the client and the Government and it's a very small proportion of what happens in public relations. I as a peer anyway have strict rules about what I can and cannot do.

"You mustn't muddle up public relations and lobbying. Lobbying is about trying to change the law or change the position or perspective of a client amongst Government.

"That needs to be regulated, of that I have absolutely no doubt at all - and nor do the legislators. 80% of MPs believe that lobbying is an important part of our lives, but they also believe, 70% believe, we should regulate it and I believe it too."

Asked about his relationship with the Prime Minister, Lord Chadlington said: "Huntsworth never gives any money to the Conservative Party and never has.

"I bought a house as part of my own place in the country. I had been trying to buy the house for the 20 years I had lived there and the person who owned it died and that's all that happened.

"I'm president of the Prime Minister's constituency. I therefore have a role in the constituency which would involve me helping in various ways locally, but that's what I do."