Mr Paterson is MP for North Shropshire and a former Northern Ireland Secretary. He was a shadow Defra minister between 2003 and 2005 and will replace Caroline Spelman.

It has emerged that the farming minister Jim Paice will also return to the back benches, with his job going to the Liberal Democrat MP, David Heath.

It is understood Mr Paice was informed that he had lost his role early yesterday afternoon as he was walking around the Livestock 2012 event, in Birmingham.

NFU President Peter Kendall said Mr Paice knew his subject inside out and brought real credibility to the post.

Peter Kendall said: “I’d like to thank Caroline Spelman for leading Defra for more than two years. The economic background has made this a particularly difficult period to be in charge of a spending department such as Defra, and she made some bold decisions on key issues, not least her commitment to tackle the devastating problem of bovine TB faced by cattle farmers. She has also worked incredibly hard to foster strong and meaningful relationships with our partners in Europe, a vital element in our efforts to ensure forthcoming reforms to the Common Agricultural Policy do not discriminate against the interests of British farmers. I wish her every success for the future.

“In turn, let me offer my congratulations to Owen Paterson on his appointment as the new Defra Secretary of State. I look forward to meeting him at the earliest opportunity to discuss the ways in which the farming industry and government can work together in future. Mr Paterson has a real appreciation of the importance of agriculture, both as a result of the strong farming presence in his North Shropshire constituency and through his previous experience as shadow Defra spokesman.

“Farming as an industry is poised to be one of the UK’s economic success stories over the coming decade. Demand for food globally will increase and there is much we can do to ensure a secure domestic supply of top quality food. To this end, the government must take a coherent approach to food and farming policy, recognising the importance of domestic production, and I am confident that Mr Paterson will prove a thoughtful and passionate advocate within government.”