A landowners’ leader said the farming community had lost a ‘key ally’ as agriculture minister George Eustice quit his post over Brexit.

Leave-backer George Eustice said he was leaving over prime minister Theresa May’s decision to allow MPs to vote on extending Brexit negotiations beyond the scheduled withdrawal date of March 29.

Country Land and Business Association (CLA) president Tim Breitmeyer, who farms on the Essex/Cambridgeshire border, said: “We are saddened to hear of George Eustice’s decision to resign as farming minister at the Department for Environment, Food and Rural Affairs. He has held the position since 2015, and has maintained a strong voice on behalf of the farming industry during that time.

“His farming background and first hand knowledge and experience have been invaluable in the many areas of his brief. The farming community has lost a key ally at this critical time for the industry, which faces significant uncertainty and change.”

Mr Eustice said he wanted to return to the backbenches “to be free to participate in the critical debate that will take place in the weeks ahead”.

He said Mrs May had undertaken a series of “undignified retreats” on Brexit and warned that prolonging the two-year Article 50 negotiation process could result in “the final humiliation of our country”, with the EU dictating the terms of any extension.

Mr Eustice said he did not believe the European Commission had behaved “honourably” during the two years of negotiations since the UK notified Brussels of its intention to quit in 2017.

He said: “They have deliberately made progress slow and difficult. They have stated in terms that they will refuse to even hold substantive negotiations on a future partnership until after we leave.

“If the position of Parliament is now that we will refuse to leave without an agreement then we are somewhat stuck.

“This is uncomfortable for everyone, but we cannot negotiate a successful Brexit unless we are prepared to walk through the door.

“We must therefore have the courage, if necessary, to reclaim our freedom first and talk afterwards. We must be ready to face down the European Union here and now.

“The absence of an agreement poses risks and costs for them too. We already know that in the event of no deal, the EU will seek an informal transition period for nine months in many areas and settlement talks could continue within this window.

“I will do what I can from the back benches to try to salvage this sorry situation and I hope that, when the moment comes, Parliament will not let our country down.”

Mr Eustice won warm tributes from many Conservative MPs, including Environment Secretary Michael Gove, who said in a tweet: “So sorry to see George go. He has been a brilliant minister and will remain a dear friend.

“He leaves an outstanding legacy, with the Agriculture and Fisheries Bills setting domestic policy for the first time in nearly 50 years. He will be very much missed.